HeaterMeter v4.1 PCB now available


 
Bryan Mayland

Bryan Mayland

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Just in time for the vague "by the end of the year-ish" timeline, HeaterMeter v4.1 boards have been finalized. This is a minor update to the v4.0 Raspberry Pi mating board. They can be identified as v4.1 models by the giant "HeaterMeter v4.1" board written across the top.



What's New
  • More ubiquitous / less ubiquitous RJ45 output jack - I thought useless RCA cables were pretty commonly found around the house so all previous HeaterMeters used an RCA jack to attach the blower. Who didn't have an old Composite video cable they were holding on to "just in case" since 1998? The new connector is an RJ45 connector. It will accept a 2 or 4 wire phone cord (RJ11) as well as an ethernet cord. If you don't have one of those 3 laying around, I am pretty sure you don't have internet access. Only 2 wires are required for normal blower operation.
  • Added servo output to the output jack - Standardized the output here so you don't have to solder servo wires to the board. To use the servo, a cable with at least 4 wires must be used. For those who have missed the boat over the past year we've been using them, servos are used as a damper to close off airflow to the pit and provide tighter control over temperatures.
  • Moved all connectors to the sides - To accommodate the HeaterMeter sitting on its edge, the power jack has been moved to the left side and blower/servo output to the right side. A HeaterMeter can now be fashioned as an ostentatious belt buckle.
  • Louder beeper operation - The buzzer is now driven 12V peak-to-peak instead of 3.3V. This should produce a stronger tone. I'm not sure if it does, but it is ear-splitting if you're less than one foot away. I still wake up hearing it.
  • Cutable traces on the pit probe jack for easier thermocouple integration on the existing pads.
  • Thermocouple addon board included with every PCB - Not for the feint of heart an AD8495 surface mount board with all the ins and outs you need to connect a thermocouple to the HeaterMeter. Jacks not included but it is designed to overlay the pit probe jack and replace it if that floats your boat. Has anyone seen a source for affordable panel mount K-type thermocouple jacks?
  • Integrated screw holes in a slightly more convenient location - Although they aren't symmetrical. So, trigger OCD in 3... 2... 1...
  • Blower output no longer has an "always on" 12V connection - +12V is only applied when the blower should be running. "Safety first!" because we're always operating our pits under the influence.
  • Header for hardware switch on the Pi - (vague hand-waving) to someday allow some sort of hardware configuration without the website. Wifi on / off or AP / Client maybe or something. Not coded yet but now the hardware is there now. You don't have to make it do that, you could make it light up some LEDs you've embedded in the HeaterMeter case to turn it onto a lantern. You're an innovative dude.

Not a whole lot different so if these features don't tickle your nethers then there's not any reason to upgrade. The board is slightly larger as well so it costs a little more. You must remove your rPi RCA composite video out jack to use this board. It can also be used as a standalone HeaterMeter if you're the anti-internet guy.



EAGLE 5 files are in GitHub. The files are individually available as well on capnbry.net which also contains the zip file to send to OSH Park (Dorkbot). Laen will also have individual boards available real soon now. Tom Kole has also been very patient with me and has a 3D printed case ready to go with a really sweet professional fit.

GitHub Wiki HeaterMeter v4.1 Hardware
GitHub Wiki HeaterMeter v4.1 Assembly (more photos coming)

There's yet another global ATmega shortage going on, so mouser won't have any MCUs available until mid-January. Boxy the HeaterMeter robot, you were supposed to be guarding them!
boxy.jpg

BEEP BEEP
 
Last edited:
Can't wait to get one, looks like some great improvements.

Bryan Mayland said:
Just in time for the vague "by the end of the year-ish" timeline, HeaterMeter v4.1 boards have been finalized. This is a minor update to the v4.0 Raspberry Pi mating board. They can be identified as v4.1 models by the giant "HeaterMeter v4.1" board written across the top.



What's New
  • More ubiquitous / less ubiquitous RJ45 output jack - I thought useless RCA cables were pretty commonly found around the house so all previous HeaterMeters used an RCA jack to attach the blower. Who didn't have an old Composite video cable they were holding on to "just in case" since 1998? The new connector is an RJ45 connector. It will accept a 2 or 4 wire phone cord (RJ11) as well as an ethernet cord. If you don't have one of those 3 laying around, I am pretty sure you don't have internet access. Only 2 wires are required for normal blower operation.
  • Added servo output to the output jack - Standardized the output here so you don't have to solder servo wires to the board. To use the servo, a cable with at least 4 wires must be used. For those who have missed the boat over the past year we've been using them, servos are used as a damper to close off airflow to the pit and provide tighter control over temperatures.
  • Moved all connectors to the sides - To accommodate the HeaterMeter sitting on its edge, the power jack has been moved to the left side and blower/servo output to the right side. A HeaterMeter can now be fashioned as an ostentatious belt buckle.
  • Louder beeper operation - The buzzer is now driven 12V peak-to-peak instead of 3.3V. This should produce a stronger tone. I'm not sure if it does, but it is ear-splitting if you're less than one foot away. I still wake up hearing it.
  • Cutable traces on the pit probe jack for easier thermocouple integration on the existing pads.
  • Thermocouple addon board included with every PCB - Not for the feint of heart an AD8495 surface mount board with all the ins and outs you need to connect a thermocouple to the HeaterMeter. Jacks not included but it is designed to overlay the pit probe jack and replace it if that floats your boat. Has anyone seen a source for affordable panel mount K-type thermocouple jacks?
  • Integrated screw holes in a slightly more convenient location - Although they aren't symmetrical. So, trigger OCD in 3... 2... 1...
  • Blower output no longer has an "always on" 12V connection - +12V is only applied when the blower should be running. "Safety first!" because we're always operating our pits under the influence.
  • Header for hardware switch on the Pi - (vague hand-waving) to someday allow some sort of hardware configuration without the website. Wifi on / off or AP / Client maybe or something. Not coded yet but now the hardware is there now. You don't have to make it do that, you could make it light up some LEDs you've embedded in the HeaterMeter case to turn it onto a lantern. You're an innovative dude.

Not a whole lot different so if these features don't tickle your nethers then there's not any reason to upgrade. The board is slightly larger as well so it costs a little more. You must remove your rPi RCA composite video out jack to use this board. It can also be used as a standalone HeaterMeter if you're the anti-internet guy.

HeaterMeterPI-brd.png


EAGLE 5 files are in GitHub. The files are individually available as well on capnbry.net which also contains the zip file to send to OSH Park (Dorkbot). Laen will also have individual boards available real soon now. Tom Kole has also been very patient with me and has a 3D printed case ready to go with a really sweet professional fit.

GitHub Wiki HeaterMeter v4.1 Hardware
GitHub Wiki HeaterMeter v4.1 Assembly (more photos coming)

There's yet another global ATmega shortage going on, so mouser won't have any MCUs available until mid-January. Boxy the HeaterMeter robot, you were supposed to be guarding them!
boxy.jpg

BEEP BEEP
Click to expand...
 
Congrats on getting V4.1 tested and released, and thanks again for all of your work developing the Heater Meter...
Boxy-Bot must have been asleep on the job, good thing I order 3 extra ATmega's and some 5v regulator boards on my last parts order!
I wish I had known about the thermocouple board when I made my parts order for the V4.1 board, I would have ordered the parts for that to... Is there a BOM for that unit somewhere?
 
RalphTrimble said:
I wish I had known about the thermocouple board when I made my parts order for the V4.1 board, I would have ordered the parts for that to... Is there a BOM for that unit somewhere?
Click to expand...
Not yet. I haven't built my prototype but have all the parts. I can already see one problem that means it won't sit flat on the board with a jack installed so so much for elegant design. Not sure how I didn't notice that when I was designing it considering I had to go out of my way to ignore it. It still might not be in the final version yet, but the schematic should be right so at least it is a useful curiosity. For perspective, here's the whole board sitting on a US dime:
 
Hi Bryan,

For thermocouple jacks, I have used the direct pcb-mount style in the past and they work quite well:
http://www.newark.com/newport-elect...ouple-connector-type-k/dp/01H0905?ost=01H0905

Otherwise, Newark also has quite a good selection of panel mount jacks for the mini-style thermocouple plugs.
http://www.newark.com/webapp/wcs/st...oreId=10194&gs=true&st=mini thermocouple jack

I looked on mouser and digikey but couldn't find anything similar for some reason. Maybe I'm using the wrong search terms.

I'm also assuming people want to use the mini-thermocouple plug instead of the giant round pin one or having to manually insert wires onto screw terminals...

Tristan
 
They will be selling 4.1 board singles but I haven't given them Laen go-ahead because I'm still working out the thermocouple addon board.
 
Thanks. So right now if I were going to build a 4.1 I'd need to buy 3 boards from OSH, right? (assuming I don't intend to hold out for the thermocouple board to be finalized and buy a single at that point)
 
Is there a way to set audible alarms? When I'm using the HM inside, I'd like it to audibly alert me that something in the oven is done (to temp). I only saw web options for email/SMS.

Sorry if this is posted in the wrong place.
 
George Glover said:
Is there a way to set audible alarms? When I'm using the HM inside, I'd like it to audibly alert me that something in the oven is done (to temp). I only saw web options for email/SMS.

Sorry if this is posted in the wrong place.
Click to expand...

The beeper on the HM does beep when the alarm(s) are triggered, at least mine does...
 
Is there any downside to using the non-P atmega vs the original spec'd part? Mouser is out of stock on the original, and even digikey is showing 0 on hand.
 
CMorris said:
Is there any downside to using the non-P atmega vs the original spec'd part? Mouser is out of stock on the original, and even digikey is showing 0 on hand.
Click to expand...
I thought that I had listed it on the parts list wiki but yeah HeaterMeter is validated on non-P ATmegas as well.
 
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