The big TEC driver thread!

[dnar]

@dnar

The standard for the onboard ISP Interface, is that male or female? Looking at pin positioning in AVR Datasheets it would be male?

What do you think on the RS232, you're the softy on this one? I have no Idea how much more work that would be on your part or if you even have time for such. Not to mention things like code space. This would be excellent in the developing process of lasers with such functions as PID tunning, Temperature readout for logging, TEC on/off?

cheers!

Hi Mate, yeah it's a 6 pin 0.1" pitch DIL un-boxed male. This is cleaverly designed to save space and allow reverse connection. Which I have done before without damage. Just for the record, I have a bootloader for Mega8 that is very small, if you wanted to get all posh we could implement serial firmware updates.

Adding a serial port is trivial but does require an MCU with a UART AND available TxD/RxD pins. So this would require a Mega8 for example.

It might even be worth considering the use of an FTDI chip and going straight to USB. The OpenSource Arduino project recently released the Uno, featuring the ATmega328 MCU and a dedicated Mega8 in place of the FTDI chip. The benefit is this solution supports host AND guest USB connections. While this is of little use to us, we could use the opensource code for the USB implementation as this will be cheaper than the FTDI route.

Of course, if everyone is happy with RS232, then this is the simplest options with minimal code overhead. My preference would be to use the MAX3311 (1xTx, 1xRx) however I dont think these are available in DIP. Just provide a boxed 10-pin DIL 0.1" header for connection to D9 via a ribbon cable if required.

I really think the best course of action is to proceed with the current design and add serial and other features in future releases, maybe once you step to SMD.

[ogoun]

I really think the best course of action is to proceed with the current design and add serial and other features in future releases, maybe once you step to SMD.

My only concern is that so many of these projects start out with good intentions, but only a few actually become a buildable, useable thing. This project looks to not only be a good design, but also looks likely to end up with a buildable (i.e. PCB, schematic, source for the micro) end product. I worry, once this design is completed, that a second design revision may be a long time coming, if ever.

I still suggest just adding RS232, using the DIP packaged MAX233, since it is simple and easy to implement. Can't the attiny24 do hardware UART? What about one of it's other dip packaged siblings?

Cheers,

Pete

[dnar]

My only concern is that so many of these projects start out with good intentions, but only a few actually become a buildable, useable thing. This project looks to not only be a good design, but also looks likely to end up with a buildable (i.e. PCB, schematic, source for the micro) end product. I worry, once this design is completed, that a second design revision may be a long time coming, if ever.

I still suggest just adding RS232, using the DIP packaged MAX233, since it is simple and easy to implement. Can't the attiny24 do hardware UART? What about one of it's other dip packaged siblings?

Cheers,

Pete

Hi Pete,

I hear ya, from what I understand Solarfire has definite plans for 2 other versions already. My concern is the opposite of your, that we keep adding functions and never arrive at V1.0! It's up to Solarfire as he is driving the hardware, he appears pretty fired up too.

The ATtiny controller include a 2-wire synchronous serial interface, but not an asychronous UART. For this you need to move from Tiny to Mega. I *could* bit-bang, but would rather not... I would prefer a dedicated UART with Interrupts. On the Maxim front, although the MAX233 does not require extermal caps, it is DIP20 and therefore requires more PCB real estate. I prefer the DIP16 MAX232A which requires only 4 x 100nF caps. It is much cheaper than MAX233 also.

I can implement anything in firmware, but my minimum requirement is hardware! Otherwise it's all just vaporware!

I will leave this call to Solarfire. Proposal:

ATmega MCU with UART and EEPROM
MAXIM 5V transciever
IDC10 header for connection to a D9 female crimp chassis connector.

[Solarfire]

My only concern is that so many of these projects start out with good intentions, but only a few actually become a buildable, useable thing. This project looks to not only be a good design, but also looks likely to end up with a buildable (i.e. PCB, schematic, source for the micro) end product. I worry, once this design is completed, that a second design revision may be a long time coming, if ever.

I still suggest just adding RS232, using the DIP packaged MAX233, since it is simple and easy to implement. Can't the attiny24 do hardware UART? What about one of it's other dip packaged siblings?

Cheers,

Pete

Sure there’s plenty of possibility to design the Alpha of TEC controllers but the maxed out build will not always be the best for the application at hand. Size is also a factor which will be a go or no go factor for some.


As far as RS232 goes, it’s pretty much getting extinct, maybe do a pole for RS232 or USB?


I kind of see a demand for a build with a small footprint to be implemented in applications and maybe a Lab style build more laid out for the development of TEC applications.

[dnar]

Sure there’s plenty of possibility to design the Alpha of TEC controllers but the maxed out build will not always be the best for the application at hand. Size is also a factor which will be a go or no go factor for some.


As far as RS232 goes, it’s pretty much getting extinct, maybe do a pole for RS232 or USB?


I kind of see a demand for a build with a small footprint to be implemented in applications and maybe a Lab style build more laid out for the development of TEC applications.

Agreed. For this 1st build, I would not recommend USB. That should be on a later board with "all the fruit".

I use Serial everyday still, with a Prolific USB/Serial converter. Adding USB to the PCB really just replaces this converter. I hope noboddy suggests a TCP/IP interface...

My vote: lets get this 1st board out as is. Future boards should have the specs' and feature set defined in stone before we commence design.

[Solarfire]

My vote: lets get this 1st board out as is. Future boards should have the specs' and feature set defined in stone before we commence design.

Agreed.. Version V1.00 underway.

[dnar]

Agreed.. Version V1.00 underway.

Cool.

I'll be honest and say that I have not looked at the code yet, work has been caos with a new product in the process of final firmware changes and the start of production has seen me working in both Sydney time and Germany time zones each and every day. Add to that I have been fighting off a cold and fever for 2 days.... It's not right to be sneezing constantly when it's 35c!!!!

I'll get to it, still waiting on consensus re the interlock window range.

[Solarfire]

Cool.

I'll be honest and say that I have not looked at the code yet, work has been caos with a new product in the process of final firmware changes and the start of production has seen me working in both Sydney time and Germany time zones each and every day. Add to that I have been fighting off a cold and fever for 2 days.... It's not right to be sneezing constantly when it's 35c!!!!

Well, I'd say easy does it dude, we're not tryin to break any TEC-Controller development speed records here now.
Speakin of time zones, don't you ever sleep?

I'll get to it, still waiting on consensus re the interlock window range.

I guess you meen the LD-Inhibit when out of range.. I'd say +/-2.5c

[dnar]

Well, I'd say easy does it dude, we're not tryin to break any TEC-Controller development speed records here now.
Speakin of time zones, don't you ever sleep?



I guess you meen the LD-Inhibit when out of range.. I'd say +/-2.5c

For the past 5 months I have worked 65hrs/week every week and sleep from 1-2am to 7am.

+/-2.5c sounds good to me. Thanks.

BTW, tomorrows forecast is 37c and thunder storms!!! The weather in Australia is really f*cked up this year... At least the bush fires have stopped.

[Solarfire]

For the past 5 months I have worked 65hrs/week every week and sleep from 1-2am to 7am.

+/-2.5c sounds good to me. Thanks.

BTW, tomorrows forecast is 37c and thunder storms!!! The weather in Australia is really f*cked up this year... At least the bush fires have stopped.

You defiantly work too much dude! Unfortunately you’re not just around the corner, id come by and pull ya out from behind your PC for beer.. that’ll sweat it out


Beyond that the weather is f*cked up everywhere. You ever been to Germany? If I add up everything we’ve had this year it may add up to 37°?


Australia was my last hope for that paradise climate change!