Rover V8
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AndreyB
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Re: Rover V8
Seems pretty close to the pretty common values from setCommonNTCSensor() method, I will add the needed invocations into your config.
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Re: Rover V8
As always there are many factors to keep in mind. I'm assuming you have a thermistor at the core of the sensor. I know many thermistors purchased from digikey and such suppliers have an absolute max power they can dissipate that's around 2mW. So to keep the sensor reliable, you probably want to keep the power it dissipates under 2mW. Also self heating tends to warp the measurement and add to the +/- tolerance of the measured readings, so higher ohms in the bias resistor has some preference. The down side is that if you choose to high of a bias resistor, you loose your resolution of the ADC, which also adds to the +/- tolerance of that readings. If you choose to low of a bias resistor, you break the sensor and you could also diminish the resolution of the ADC. So you want to choose a value that is not to high, and not to low.
Any how, that said, once upon a time, I put together a version of the attached spread sheet. This allows you to put in what values you have, and it shows you a graph of what the ADC would see. You can eyeball this graph to get a feel for when you will have a poor +/- tolerance from the ADC. The more horizontal the graph line, the more +/- you'll have to consider for your ADC reading. You can modify this spread sheet to meet your needs, and perhaps fine tune the ADC to be more precise where you might want more precision. I drafted it with the suggested 5V supply and 2.7kohm bias resistor. However take not that with your sensor it slightly exceeds the 2mW at 0C to 20C. Also note it looks like your measurements around 50C were probably a bit off. You can modify the ohms for each reading to show the min and max and such.
Any how, that said, once upon a time, I put together a version of the attached spread sheet. This allows you to put in what values you have, and it shows you a graph of what the ADC would see. You can eyeball this graph to get a feel for when you will have a poor +/- tolerance from the ADC. The more horizontal the graph line, the more +/- you'll have to consider for your ADC reading. You can modify this spread sheet to meet your needs, and perhaps fine tune the ADC to be more precise where you might want more precision. I drafted it with the suggested 5V supply and 2.7kohm bias resistor. However take not that with your sensor it slightly exceeds the 2mW at 0C to 20C. Also note it looks like your measurements around 50C were probably a bit off. You can modify the ohms for each reading to show the min and max and such.
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Re: Rover V8
got it. thanks!
we can also feed 3.3v instead of 5, which will help keep power to be dissipated lower…
actually, the first two sensors are sort of industrial solutions, OEM manufactured, etc (don't know which element is inside)
Probably, I will build my own air intake temperature sensor based on one of those small NTC resistors you are talking about.
we can also feed 3.3v instead of 5, which will help keep power to be dissipated lower…
actually, the first two sensors are sort of industrial solutions, OEM manufactured, etc (don't know which element is inside)
Probably, I will build my own air intake temperature sensor based on one of those small NTC resistors you are talking about.
Re: Rover V8
speaking of voltage meter.
I am using PA0 input.
we need 5V at the input of opamp.
Will it be okay, if i use
R252 33K, R253 - 0, C250 - 10K
R254, R255 - 1.5K
R250, R251 - empty.
I'd also adjust those settings in TS.
I am using PA0 input.
we need 5V at the input of opamp.
Will it be okay, if i use
R252 33K, R253 - 0, C250 - 10K
R254, R255 - 1.5K
R250, R251 - empty.
I'd also adjust those settings in TS.
Re: Rover V8
Speaking of TPS. I have this one: (just search 'throttle position sensor' on that page)
http://www.britishv8.org/articles/rover-14cux-efi.htm
It's a potentiometer. I wonder if it would be safe feeding plain 5V (without any current limiting resistor on the feed line). I can not afford any mistakes with this one.
http://www.britishv8.org/articles/rover-14cux-efi.htm
It's a potentiometer. I wonder if it would be safe feeding plain 5V (without any current limiting resistor on the feed line). I can not afford any mistakes with this one.
Re: Rover V8
R253 and C250 are a generic low pass filter. You can use different values, and you can vary these by quite a bit. I would suggest you try to keep close-ish to a cap around .01uF for C250 and a resistor under 1k for R253. I would also suggest some high ohms for R251. The high ohms would pull the input low if it's not connected to a sensor, but should be high enough to not significantly change the signal. Do you have something in the 100k ohm or above range?
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Re: Rover V8
i have a full set of 1206 size. i'd try to get 0805.
the question is it is a voltage meter, the input voltage should be somewhat 12-14 or even more volts.
that's why i am asking... (the first question)
and there's still a question regarding tps. is it safe to feed 5v directly fom the power supply unit? won't the high current kill it?
the question is it is a voltage meter, the input voltage should be somewhat 12-14 or even more volts.
that's why i am asking... (the first question)
and there's still a question regarding tps. is it safe to feed 5v directly fom the power supply unit? won't the high current kill it?
Re: Rover V8
I haven't tested it, but in theory, it has thermal and current shutdowns, so it should be safe if you short to GND. However if you short to 12V, that would probably be bad, as there isn't anything to pull it down to 5V, so the 5V would go above 5V. So don't connect 12V to the 5V.
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Re: Rover V8
spent half a day in the garage.
managed to install the assembled crank pulley and put the belts back on to their original location. now the car starts again. (didn't adjust the weights though - thinking of adding couple of nuts on the bolts on that pulley)
btw, got the video of cranking. i guess, i could try calculating the cranking speed. i believe, it's somewhat 120-150 rpm.
Now I got the trigger wheel installed!
The next problem is fabricating the sensor mount. Should it be made of aluminum? Or could I use steel? (It's a VR sensor and I've read somewhere, to ensure proper operation I don't want to have any substances that change magnetic field).
Originally, in many megasquirt setups, the sensor mount was expected to bolt on to the water pump cover with two bolts. I got just one. Instead of the second one (the upper one) I have a hole without a thread in the water pump cover. I guess the bolt was broken and left inside the block. To restore the old thread, I'd have to remove the rad, the crank pulley (again?!) and then the water pump, which is quite a messy job. to tap the new thread in water cover, I'd still have to remove the rad… for now i think one bolt mount should be sufficient.
the mount itself is a bit tricky to manufacture. the mounting plain of the water pump cover is just 5mm from the center plain of my trigger wheel...
managed to install the assembled crank pulley and put the belts back on to their original location. now the car starts again. (didn't adjust the weights though - thinking of adding couple of nuts on the bolts on that pulley)
btw, got the video of cranking. i guess, i could try calculating the cranking speed. i believe, it's somewhat 120-150 rpm.
Now I got the trigger wheel installed!
The next problem is fabricating the sensor mount. Should it be made of aluminum? Or could I use steel? (It's a VR sensor and I've read somewhere, to ensure proper operation I don't want to have any substances that change magnetic field).
Originally, in many megasquirt setups, the sensor mount was expected to bolt on to the water pump cover with two bolts. I got just one. Instead of the second one (the upper one) I have a hole without a thread in the water pump cover. I guess the bolt was broken and left inside the block. To restore the old thread, I'd have to remove the rad, the crank pulley (again?!) and then the water pump, which is quite a messy job. to tap the new thread in water cover, I'd still have to remove the rad… for now i think one bolt mount should be sufficient.
the mount itself is a bit tricky to manufacture. the mounting plain of the water pump cover is just 5mm from the center plain of my trigger wheel...
Re: Rover V8
thinking of adding my own avr-based coolant temperature gauge. i want to tap off the wire from sensor either from the very input (5v+pull-up), or from the discovery board. not sure, which is better.
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AndreyB
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Re: Rover V8
why not the rusEfi LCD?
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Re: Rover V8
1. don't know how to configure it to display the needed info.
2. it's not that readable compared to a dedicated needle gauge.
3. thinking of using a digipot to control the native bimetal gauge
4. don't want to occupy the lcd with just that single task.
2. it's not that readable compared to a dedicated needle gauge.
3. thinking of using a digipot to control the native bimetal gauge
4. don't want to occupy the lcd with just that single task.
Re: Rover V8
How about a signal stream like this sensor --> rusEFI --> serial stream --> AVR --> gauge.
I would like to encourage this approach, as I see the long term using serial controlled needle gauges as LCD's can have glare issues. I see LCD as good for diagnostics, and needle good for tach, RPM, temp, ect. The LCD for flashing warnings, and more dynamic information, like warning your due for an oil change, or sensor XYZ measures incorrectly, ect.
If you want to develop a low cost guage option, that would be great. Perhaps putting a needle on a RC style servo like the MG995, and mounting it in spray paint cap wold make for a low cost assembly. Here's a link to an MG995, there are many suppliers for this servo, this one is just a link that will probably be there for a couple days. http://www.amazon.com/365buying-Tower-Pro-MG995-Torque/dp/B0098M4R4Q I mention the MG995 as it works well with this https://www.sparkfun.com/products/9014 which uses an AVR processor. Combining these pieces can probably get you a needle style gauge for less than $20 in materials.
Other serial stream gauge options, at a higher price point, but less DIY can be found here.
http://www.plxdevices.com/ Very configurable, and does allow digital streamed data to be displayed. However glare can be an issue.
http://www.speedhut.com/gauge/G-FUELLEV-01/1/Speedhut-Fuel-Level-Gauge-(programmable) Real needle display which is less configurable but less glare issues, I think this can be programmed via digital stream. I've inquired to learn more.
I would like to encourage this approach, as I see the long term using serial controlled needle gauges as LCD's can have glare issues. I see LCD as good for diagnostics, and needle good for tach, RPM, temp, ect. The LCD for flashing warnings, and more dynamic information, like warning your due for an oil change, or sensor XYZ measures incorrectly, ect.
If you want to develop a low cost guage option, that would be great. Perhaps putting a needle on a RC style servo like the MG995, and mounting it in spray paint cap wold make for a low cost assembly. Here's a link to an MG995, there are many suppliers for this servo, this one is just a link that will probably be there for a couple days. http://www.amazon.com/365buying-Tower-Pro-MG995-Torque/dp/B0098M4R4Q I mention the MG995 as it works well with this https://www.sparkfun.com/products/9014 which uses an AVR processor. Combining these pieces can probably get you a needle style gauge for less than $20 in materials.
Other serial stream gauge options, at a higher price point, but less DIY can be found here.
http://www.plxdevices.com/ Very configurable, and does allow digital streamed data to be displayed. However glare can be an issue.
http://www.speedhut.com/gauge/G-FUELLEV-01/1/Speedhut-Fuel-Level-Gauge-(programmable) Real needle display which is less configurable but less glare issues, I think this can be programmed via digital stream. I've inquired to learn more.
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Re: Rover V8
i'd love to - how do i get that stream? from the same serial port used by devconsole? then it won't be working while i use devconsole? people say, serial is point to point protocol, rather than multipoint.
btw i got stepper motors used in modern dashboards got a somewhat working tacho.
btw i got stepper motors used in modern dashboards
got a somewhat working tacho.Re: Rover V8
Sounds like I've got 1/2 of the development team, now I just need to convince russian russian is now racing, so he probably won't get to reply until Monday.
The serial stream for OpenServo would be I2C for multi node, but can take PWM for single node. It's a fairly simple bus, with fairly simple hardware requirements, basically you add a pull up resistor to the bus, then either the master or the slave will switch between pull down and floating. If either the software or hardware has a delay, the buss auto-magically slows down to account for such issues. Data rates of 400k bits/s and a couple meters are easily obtained.
More about I2C including bitbang code found here http://en.wikipedia.org/wiki/I%C2%B2C
Example STM32F4 code found here http://eliaselectronics.com/stm32f4-tutorials/stm32f4-i2c-master-tutorial/
Any how, the rusEFI firmware and perhaps the dev console (or TS file) will probably need some changes to make this work. I'll see if I can get him on board with this approach later today. I know he wants to focus on IAC and other engine control parameters, so I'm not sure how he'll prioritize gauges at this point. I think he'll either say it's easy enough that he'll just do it, either that or he'll say he'll do it once he has hardware and a need. Any chance this is something that someone else can try to tackle? It's a bit easier of a change than what russian is working on right now, so it should be something a lesser skilled person can obtain. Perhaps that would mean more people can contribute this chunk of code other than just russian. I'll inquire with russian, but if someone else chimes in I'll help support the effort, AKA do you want me to buy you a OS board and servo motor.
russian is now racing, so he probably won't get to reply until Monday. The serial stream for OpenServo would be I2C for multi node, but can take PWM for single node. It's a fairly simple bus, with fairly simple hardware requirements, basically you add a pull up resistor to the bus, then either the master or the slave will switch between pull down and floating. If either the software or hardware has a delay, the buss auto-magically slows down to account for such issues. Data rates of 400k bits/s and a couple meters are easily obtained.
More about I2C including bitbang code found here http://en.wikipedia.org/wiki/I%C2%B2C
Example STM32F4 code found here http://eliaselectronics.com/stm32f4-tutorials/stm32f4-i2c-master-tutorial/
Any how, the rusEFI firmware and perhaps the dev console (or TS file) will probably need some changes to make this work. I'll see if I can get him on board with this approach later today. I know he wants to focus on IAC and other engine control parameters, so I'm not sure how he'll prioritize gauges at this point. I think he'll either say it's easy enough that he'll just do it, either that or he'll say he'll do it once he has hardware and a need. Any chance this is something that someone else can try to tackle? It's a bit easier of a change than what russian is working on right now, so it should be something a lesser skilled person can obtain. Perhaps that would mean more people can contribute this chunk of code other than just russian. I'll inquire with russian, but if someone else chimes in I'll help support the effort, AKA do you want me to buy you a OS board and servo motor.
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Re: Rover V8
i don't think i need this os board. i am driving the stepper motor (and thus the needle) from attiny, powered from 5v. i think from the steppermotor' point of view it doesn't matter where i get the data from - either directly the adc from the thermistor, or from the serial port (decryping stream to devconsole), or from pwm & rc filte, or i2c.
it's not that it want immediately, but i want to have it working by spring - hopefuly i will entertain myself in december/january. but anyhow, by that time i will have to know which is the best option to capture data... (could it be serial sniffer, btw? what's so bad about it?)
it's not that it want immediately, but i want to have it working by spring - hopefuly i will entertain myself in december/january. but anyhow, by that time i will have to know which is the best option to capture data... (could it be serial sniffer, btw? what's so bad about it?)
Re: Rover V8
speaking of i2c. i got this fatory-calibrated pressure/temperature sensor
http://www.ebay.com/itm/BMP085-Barometric-Barometer-Digital-Pressure-Sensor-Module-Board-For-Arduino-S9-/251379624660?
that would be nice to add support for such thing (intake air temperature, second pressure sensor). it seems to be cheaper than a dedicated air temperature sensor I was going to purchase).
besides, it could serve as a reference gauge for the main MAP sensor.
http://www.ebay.com/itm/BMP085-Barometric-Barometer-Digital-Pressure-Sensor-Module-Board-For-Arduino-S9-/251379624660?
that would be nice to add support for such thing (intake air temperature, second pressure sensor). it seems to be cheaper than a dedicated air temperature sensor I was going to purchase).
besides, it could serve as a reference gauge for the main MAP sensor.
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AndreyB
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Re: Rover V8
Now time to email me a patch with this chips driver
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Re: Rover V8
If I only knew how to do that 
Hope in December/January I'll have some time to try to get through that explanation on the russian forum…
Hope in December/January I'll have some time to try to get through that explanation on the russian forum…
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Re: Rover V8
If that's a gauge then it has to be CAN I guess. We have CAN already, CAN is the automotive serial - profit.kb1gtt wrote:How about a signal stream like this sensor --> rusEFI --> serial stream --> AVR --> gauge.
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Re: Rover V8
I believe, anything will do, if I have the necessary hardware. If it is CAN (is it implemented in software?), I am afraid, I'd need couple of those boards I got from oshpark. And I'd need a CAN interface onboard of my dashboard (gauge) controller, which makes it rather expensive. Or there is a way to bitbang CAN host? or there is a way to manage without CAN bus transceivers at all?
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Re: Rover V8
rusEfi has some very basic CAN support already
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Re: Rover V8
what is the can bus pid for coolant gauge? 
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Re: Rover V8
Unfortunately you would need to figure all this out. I simply do not have time to be involved with CAN or gauges at this point 
http://sourceforge.net/p/rusefi/code/HEAD/tree/trunk/firmware/hw_layer/can_hw.cpp
http://sourceforge.net/p/rusefi/code/HEAD/tree/trunk/firmware/hw_layer/can_hw.cpp
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Re: Rover V8
btw, speaking of CAN. Jared, am I right that
http://www.nxp.com/documents/data_sheet/TJA1050.pdf
or
http://ww1.microchip.com/downloads/en/devicedoc/21667d.pdf
in SO-8
is a direct replacement for SN65HVD230?
(I am making an order from the seller who has such chips in his price list, so that would be handy for me)
hm. seems they require 5v supply voltage…
http://www.nxp.com/documents/data_sheet/TJA1050.pdf
or
http://ww1.microchip.com/downloads/en/devicedoc/21667d.pdf
in SO-8
is a direct replacement for SN65HVD230?
(I am making an order from the seller who has such chips in his price list, so that would be handy for me)
hm. seems they require 5v supply voltage…
Re: Rover V8
seems it would be safe to use any of those transievers.
e.g. see this funny document: http://e2e.ti.com/cfs-file.ashx/__key/telligent-evolution-components-attachments/00-142-01-00-00-93-94-72/CAN_5F00_Comparison_5F00_TJA1050_5F00_HVD230.pdf
the only tricky part is communicating between discovery board and the chip. both of them require at least 4.5V. Probably I'd need to use a voltage divider to connect it to the discovery board (unless it is 5v tolerant on those pins - could anyone comment on this?)
so probably I'll order a TJA1050, a MCP2551 and MCP2515 as a controller. the scheme would be mega8->MCP2515->MCP2551<==>TJA1050<-Dicsovery, right?
e.g. see this funny document: http://e2e.ti.com/cfs-file.ashx/__key/telligent-evolution-components-attachments/00-142-01-00-00-93-94-72/CAN_5F00_Comparison_5F00_TJA1050_5F00_HVD230.pdf
the only tricky part is communicating between discovery board and the chip. both of them require at least 4.5V. Probably I'd need to use a voltage divider to connect it to the discovery board (unless it is 5v tolerant on those pins - could anyone comment on this?)
so probably I'll order a TJA1050, a MCP2551 and MCP2515 as a controller. the scheme would be mega8->MCP2515->MCP2551<==>TJA1050<-Dicsovery, right?
Re: Rover V8
moreover, according to this doc.
http://www.matejk.cz/zdroje/mcp2515-avr-can-spi.pdf
I should be able to manage without transceivers! right?
http://www.matejk.cz/zdroje/mcp2515-avr-can-spi.pdf
I should be able to manage without transceivers! right?
Re: Rover V8
A quick look shows they are very close, so perhaps. I'll have to look over the datasheets in more detail, but I wonder if pin 8 is the same for them all. If I don't reply before to long, ping me and I'll look at it again. I may see a flash in the pan and forget to look into this.
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Re: Rover V8
I'll order these chips now. if everyhing goes well, in december we are moving to india till april. the plan for this time is to build a can sniffer and to try indian pcb manufacturing service.
i've seen a page in german with source code and files for such a sniffer, which should simplify this task.
i' ve found pids for vag, bmw and fiat. now i thing i need to find out the data rate of the transmiting party and match it to the receiver (or may be i just got it wrong - some guys discussed why they failed to make their can network work).
i've seen a page in german with source code and files for such a sniffer, which should simplify this task.
i' ve found pids for vag, bmw and fiat. now i thing i need to find out the data rate of the transmiting party and match it to the receiver (or may be i just got it wrong - some guys discussed why they failed to make their can network work).
Re: Rover V8
It has been too long since I have worked on CAN..
Anyway there I recall a pitfall with using a 5V CAN transceiver with a 3V3 MCU. For now stick with the 3V3 transceiver on 3V3 MCUs. For 5V (like the MCP2515) you can use the other transceivers.
Using the MCP2515 back to back on a breadboard would probably not need a transceiver, but this is no good practice when connecting to an actual bus (I am not even sure it would work without transceiver).
I have 2 pieces of 320x240 2,2" LCD screens laying around, I was thinking of creating a single DIN radio display module to replace gauges. I think there should be a market for that kind of stuff, let me know if I should put some effort in it!
Anyway there I recall a pitfall with using a 5V CAN transceiver with a 3V3 MCU. For now stick with the 3V3 transceiver on 3V3 MCUs. For 5V (like the MCP2515) you can use the other transceivers.
Using the MCP2515 back to back on a breadboard would probably not need a transceiver, but this is no good practice when connecting to an actual bus (I am not even sure it would work without transceiver).
I have 2 pieces of 320x240 2,2" LCD screens laying around, I was thinking of creating a single DIN radio display module to replace gauges. I think there should be a market for that kind of stuff, let me know if I should put some effort in it!