Search found 45 matches

by Horizenjob
Thu Jun 23, 2016 3:06 pm
Forum: Hardware
Topic: Weatherpack - How to Build a Wiring Harness
Replies: 5
Views: 948

Re: Weatherpack - How to Build a Wiring Harness

Proper crimping, soldering and wire wrapping provide gas tight connections. That way there will never be oxide between connecting parts. One reason you get such weird results with poor crimps is that metal oxides function like diodes. They will look OK if you use an Ohm meter one direction, but not ...
by Horizenjob
Mon May 09, 2016 3:49 am
Forum: Hardware
Topic: Soldering tricks & hints
Replies: 29
Views: 5551

Re: Soldering tricks & hints

Perhaps that was a lack of rinsing? You can dissolve the flux etc. but then you need to rinse it away or it's still there. Gasoline seems a bad idea, mineral spirits would be far safer. I don't recollect something like that being used on any assembly lines or rework stations that I've see. Only use ...
by Horizenjob
Sat Apr 09, 2016 1:55 am
Forum: Hardware
Topic: Frankenso: tpic8101 explosion
Replies: 26
Views: 3675

Re: Frankenso: tpic8101 explosion

I see a slight miss of the drill as a potential source for no connection,
Yes, didn't mean to suggest that comment had anything to do with the problem here. It looks like you have very generous antipads, so that's not a problem at all.
by Horizenjob
Fri Apr 08, 2016 6:39 pm
Forum: Hardware
Topic: Frankenso: tpic8101 explosion
Replies: 26
Views: 3675

Re: Frankenso: tpic8101 explosion

One thing I thought would be useful was to add a couple of mils to the pad size. My fab place gave different specs for IPC class 2 and class 3 boards. Class 3 boards are to a higher reliability spec. The issue is even if the drill hole is completely in the pad, it can be right up against where the t...
by Horizenjob
Fri Apr 08, 2016 1:30 pm
Forum: Hardware
Topic: Frankenso: tpic8101 explosion
Replies: 26
Views: 3675

Re: Frankenso: tpic8101 explosion

For this to happen the 5V plane would need to be shifted a bit so the clearance ring was not enough. The the via plating would short 12V to 5V. Anerror like that should potentially show up other places on the board. Looking at the top and bottom of the via and other vias would give you an idea of ho...
by Horizenjob
Fri Apr 08, 2016 1:03 pm
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

At the very top of the datasheet Maxim claims 40 mA max for IN1+, IN1-, IN2+, IN2-. It's nice the Maxim part is auto qualified. They don't mention ESD in the datasheet though. The TVS I am using on ECU inputs are 0603 SURGX and cost about $0.09. OEMs avoid this cost, but I don't think it's a high co...
by Horizenjob
Fri Apr 08, 2016 6:05 am
Forum: Hardware
Topic: Frankenso: tpic8101 explosion
Replies: 26
Views: 3675

Re: Frankenso: tpic8101 explosion

Do you guys know why yet? Is it just that individual board?
by Horizenjob
Fri Apr 08, 2016 4:35 am
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

Not to knock anyone here, but I think a good, hard look at the datasheet for the MAX992x chips as well as a deep study of the evaluation kits I really have read the datasheet. Honest. Several times even. There is not much info in the evaluation kit information, so not so sure how deep it can be stu...
by Horizenjob
Wed Apr 06, 2016 5:54 pm
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

I'm using the Maxim 9926, so am expecting the chip to reference the common mode voltage. It appears to have an internal 100K resister setting the positive leg to the internal bias voltage. It doesn't seem like a very strong connection to the bias voltage though. Do you think I should use external pa...
by Horizenjob
Wed Apr 06, 2016 2:23 pm
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

I should be more clear. The diodes I am using to clamp are between the signal lines, they limit the differential voltage to a diode drop, it will never exceed something like 1.2V and maybe not reach even that.
by Horizenjob
Wed Apr 06, 2016 4:18 am
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

The signal swing is what I was working on. The above trace shows the signal with a pair of diodes for voltage clamps. It seems better to do the clamp off the chip for the reasons you mention, it just doesn't make sense to dump current into a little chip. These diodes gave a .9V signal swing and that...
by Horizenjob
Sat Apr 02, 2016 5:53 am
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

Sorry I upload the wrong file, I converted it then clicked on the wrong one. Funny the forum software let me delete the file but not reload it. Here is what the trace looks like. More or less what you would expect. I'll try a faster RPM on the drill press tomorrow. I was a little surprised how low t...
by Horizenjob
Fri Apr 01, 2016 10:31 pm
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

Hi Jarrod, thanks. Meant to answer earlier. I think I either did the math in my head or also used a different trace, anyway you did it right. Finally got to run the VR sensor with a diode clamp. I'm much happier. We'll see if the Maxim chips are happy too. This is with a pair of scrap diodes I had l...
by Horizenjob
Fri Apr 01, 2016 5:02 pm
Forum: Hardware
Topic: Frankenso: tpic8101 explosion
Replies: 26
Views: 3675

Re: Frankenso: tpic8101 explosion

There is more glamor in this business than people realize! :lol:

I've had melted parts hit my face when they explode, you should wear safety glasses, but my generation tends to ignore all that stuff....
by Horizenjob
Sat Mar 26, 2016 11:00 pm
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

Fixed the picture for you, I meant to upload a jpg but usually I especially intend to do that after the forum refuses to load the tiff. THis forum did allow it though so my normal thought process was interrupted! :)
by Horizenjob
Sat Mar 26, 2016 4:02 pm
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

I spent more time thinking about the soft startup circuit. A 1 Ohm power resistor on the power connection would do everything I want except maybe cause a 1V drop during engine cranking. You could use a mosfet to bypass the power resistor after the system powers up, but then you could use a mosfet to...
by Horizenjob
Wed Mar 23, 2016 7:15 pm
Forum: Hardware
Topic: VR board
Replies: 51
Views: 4294

Re: VR board

I read the datasheet for the Comchip 1206 diode more carefully. The package is an FRP substrate with a glass passivated diode embedded. So it may be a reasonable match for the thermal coefficient of the board. It was interesting to read the STMicro datasheet for the support chip and see the example ...
by Horizenjob
Fri Mar 18, 2016 5:18 pm
Forum: Hardware
Topic: L9779WD-SPI - Multifunction IC for engine management system
Replies: 11
Views: 1819

Re: L9779WD-SPI - Multifunction IC for engine management sys

I'm not a Linux guy so, as much as I like Freescale products they are a no for me for limited production runs or personal use. If the chip looks good then I will get some boards made Hi Rhinoman. I must have given the wrong impression somewhere. Freescale doesn't even support Linux, I don't think. ...
by Horizenjob
Thu Mar 17, 2016 6:29 pm
Forum: Hardware
Topic: L9779WD-SPI - Multifunction IC for engine management system
Replies: 11
Views: 1819

Re: L9779WD-SPI - Multifunction IC for engine management sys

This would be a great chip to use with my CPU cards. That's basically why I kept the analog on the CPU board and put the external driver stuff on the partner card. Not having these features married is a good thing, it's easy to imagine lots of driver boards. Horizonjob is working on an SPC56 based E...
by Horizenjob
Wed Mar 16, 2016 5:27 pm
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

Thanks for the pointer to the guide, I'll look at it. They have a PTC on some of the Freescale demo boards. I think it was the datasheet's temperature curves that made me pause. The only place I am using one now is a little one between the external analog ground and the internal ground. This is in c...
by Horizenjob
Wed Mar 16, 2016 2:45 am
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

Thanks. Yup, the board assembly and programming is the priority now. Interesting idea on the staggered pins. I didn't mention above but I decided that the partner board with the drivers would be layed out with the sockets on the correct grid. I'll solder in th pins myself and will do it with a proto...
by Horizenjob
Tue Mar 15, 2016 5:15 pm
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

Hmmm, now you have me wondering, if the parents don't provide a name, do the give you a number or something, or could I actually be a nobody? Geez, forgot I left this thread behind so long ago. I don't think they let you have a nobody. Turns out they start calling you up on the phone after a day or...
by Horizenjob
Sat Mar 05, 2016 5:50 am
Forum: Hardware
Topic: VR board
Replies: 51
Views: 4294

Re: VR board

Keep in mind you want your 10k resistors to be large enough that you get enough energy at low RPM to accurately detect the signal, but don't have to much energy at high high temperature and high RPM's. If you limit your detectable voltages with external clamping diodes you'll limit the range you ca...
by Horizenjob
Fri Mar 04, 2016 10:44 pm
Forum: Hardware
Topic: VR board
Replies: 51
Views: 4294

Re: VR board

I've been wondering on this VR sensor stuff a bit now too. I'm using the MAX9926 on my 5634 board and I'm concerned about how to handle the inputs and wether or not I should provide protection. On my prototype board I provided for Bussmann SURGX ESD protectionTVS diodes. They are 0603 and easy to us...
by Horizenjob
Thu Jan 28, 2016 3:41 pm
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

So the dev_console is the laptop side of the ECU interface? I'll take a look but it will be a couple of days. While downloading the code the only special handling is to confirm that each byte is echo'ed by the ECU before pushing the next byte down the line. That way you can check for errors and mayb...
by Horizenjob
Thu Jan 28, 2016 2:59 am
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

The 5634 flash memory is organized in pages. It has a bunch of pages and they have different sizes. In o5e it was hard coded to use one size page at a couple of different addresses. I made a little structure that described the pages, their memory addresses, what sizes they were and some register bit...
by Horizenjob
Wed Jan 27, 2016 6:54 am
Forum: Hardware
Topic: Another ECU...
Replies: 69
Views: 8359

Re: Another ECU...

I have a dev board from Freescale, I've been able to use their tools to program it. Last spring when I started on this I made some fixes for Mark E. to handle different size flash pages. Got a pile of parts in from Digikey today. One irritating thing was I got some parts on cut tape instead of Digir...
by Horizenjob
Tue Jan 26, 2016 2:50 am
Forum: Hardware
Topic: KiCad questions
Replies: 7
Views: 1272

Re: KiCad questions

They were pretty clear about actually printing a hole in the soldermask. Maybe it's the washing cycles after assembly they are concerned about. I was a little surprised the hole would be big enough to help drain the hole. I'll ask if ACPCB uses a solder stencil. The person who mentioned printing the...
by Horizenjob
Mon Jan 25, 2016 2:13 am
Forum: Hardware
Topic: KiCad questions
Replies: 7
Views: 1272

Re: KiCad questions

OK, so don't include the mask in the pad creation and then draw the spots that I don't want the mask. That makes sense, now that you point it out. When they print the solder mask, when they are tenting a via they actually leave a microscopic hole in the middle so that cleaning and plating fluids wil...
by Horizenjob
Sun Jan 24, 2016 11:15 pm
Forum: Hardware
Topic: KiCad questions
Replies: 7
Views: 1272

Re: KiCad questions

My problem is that I drew what I wanted the solder mask to look like under the chip, but the drawing seems to be a negative image, so none of the solder mask I specified showed up on the board. In the picture below the magenta area under the chip should be solder mask, but it' missing on the board a...