Robert's 0.6-alpha Jaguar Build

[E4ODnut]

Correct, and as I read the data sheet it states that input voltage range is -0.3 to VCC +0.3 volts.

[Fred]

Yes, but the schematic is part of the use-case, do not forget it.

[E4ODnut]

Sorry, I have no idea what you are talking about.

[Fred]

See you day after tomorrow, will explain then. Busy busy day today.

[E4ODnut]

Update after the get together at Sim's.

Board is completely populated with the exception of D24 through D27 (short on the BOM but Andy is aware of it). Analog 5 volt clamp circuit checks OK. Both power supplies check OK. Cool-EFI USBDM with ribbon cable requires the 6 pin header to be installed. After some confusion about the appropriate driver the USBDM is running. Andy now has a link to it on his site and it runs under Win 7. After much difficulty I was able to download the serial monitor .s19 using the HCS12 programmer included with the free edition of Code Warrior. Similar situation trying to get the bench test .s19 loaded. Eventually Free EMS loader was successful using com3 and unchecking "ripping". As it stands now the firmware appears to be running but EM Studio is not happy with it. I've had no success trying to get Megatunix to communicate with Jaguar.

I fully expected to have some hardware issues as those fine pitch SMDs are a real challenge for me. Having gotten this far it looks like I may have dodged that bullet.

We're making progress. It is slow, somewhat frustrating but not entirely unexpected. Hopefully we can get the communication issue sorted out soon so I can connect some I/Os and put it on the simulator.

[Fred]

Did you wash your board down with alcohol thoroughly? viewtopic.php?f=9&t=1952

Flux between comms pins and each other or ground or power will screw you up in insidious ways.

Fred.

[E4ODnut]

Yes I did, but I can do it again.

[Fred]

Well, if you did it, then that's likely not the issue, so hold off, I guess. Are all of the through hole joints well flowed? Some are easyish to leave a bit dry.

[E4ODnut]

I'm sorry I didn't bring the board with me on the week end now so you could have critiqued it. I took a lot of care in assembly and I'm confident the through holes are all good. I'm even fairly pleased with the SMDs. All joints are nice and shiny with good fill (unless I missed something). My old eyes aren't great, but I have a lighted arm magnifier and I double check with a 10x loupe through the magnifier.

[Fred]

No worries, sounds like you know what you're doing. A magnifying glass does help, though I never use one and get by OK. You're right that you should have brought it, you might have got praise instead of critique ;-) Instead, though, take some pictures of the CPU and comms stuff up close on both sides if you want some remote review. I did Andy's early reviews this way to great success :-)