New Pi Zero $5 stripped down RasPi


 
Just tried and nope, it won't boot with the September snapshot, but it will with updated rpi firmware files.

You'll need to download https://github.com/Hexxeh/rpi-firmware/archive/master.zip for the updated bootcode.bin, fixup.dat and start.elf files.

You can do this 2 ways:

1) if your system is already booted, replace the existing bootcode.bin, fixup.dat and start.elf in the /boot folder using scp then power off and put the card into the Pi Zero.

2) using an SD card reader, replace the the existing bootcode.bin, fixup.dat and start.elf files in the root folder of the SD card.

You can also download my recently compiled snapshot that contains the firmware from here. It should run on everything from the original Pi B all the way up to the Pi Zero.
 
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I decided to enhance my Pi Zero this evening by directly wiring it to a small 4 port USB hub.

I epoxied in some plastic standoffs into the case, then I soldered the 2 x 5v power and 2 x USB data wires from the pads on the underside of the Pi Zero directly to the USB hub.

I can now choose to power it via the micro usb power port on the pi zero or through the 5v powered adapter that came with the hub. I also have 4 powered USB ports that don't require any OTG adapters!

 
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Ok, I just got my two chip computers in and I have to say this would be a great platform for a cheaper heatermeter. It really has everything except the ADC, and a thermocouple amp(if you need one). It is smaller, it runs linux, already has wifi and bluetooth. I think a cleverly designed daughter board could serve as a carrier for jacks, and an lcd if desired. Or skip the lcd and setup the wifi via bluetooth, and then configure vui a web based ui, and it is tiny!

$9 for a chip, or $35 for a pi + $15 for wifi, dont get me wrong, I have many a pi, and I love them, but this may be even better.
 
I've got my CHIP's too, but must say I am a bit disappointed in it's performance. Not only is it the smallest and cheapest computer in the world it may also be the slowest computer in the world too, web browsing was just painful in my brief experiment with it....
 
Mine does not seem so bad. Compared to a raspberry pi v1. I think it will only get better. I really like that it has BLE4 and wifi, and a battery charger on board. No extra $$ necessary.
 
Yeah it definitely is not up to the Pi in terms of speed, but it is much much faster than the old WRT54GL we used to run on. It is probably about Pi 1 in terms of performance, which is great for HeaterMeter because we don't need to run a web browser or anything. The performance of all the I/Os is equal as well so it is a transparent replacement as far as end user experience. We'll still use the ATmega though as the base microcontroller because the ARM on Linux can't perform as well as a dedicated microcontroller.

It is definitely slower than my Nexus 7 (2012) for web browsing and such but web browsing is an insanely CPU intensive task that we all sort of take for granted now. As a tiny Linux server though it works great, I've got one with MQTT, sqlite3, node-red, apache and PHP and the performance of serving not-very-complex pages is indistinguishable from my full i3 3.4GHz Linux server.
 
Hey everyone! First post...

I just finished building two 4.3 HMs (minus the 3 LEDs). I have a lot of experience with building circuits so I'm fairly certain the PCBAs themselves are fine. Bought a Pi Zero, uploaded the files from the Installation guide, booted it up using USB power and the HM atmega looks like it programmed correctly (says no pit probe etc). No issues so far. Wifi dongle even works and shows up on my network.

I remove USB power and power the HM from the barrel plug using a 12v supply I have. Couple seconds later, the PiZero stops responding and it's very hot (definitely fried).

Two questions:
1. Since I did not install the 3 LEDs yet, does this have anything to do with the Pi being destroyed? I took a look at a screenshot of the board layers from a routing program that someone posted but I can't figure it out on my own (ME by trade, not EE). I have another Pi on the way, but ideally i'd like to make sure I know what's up before installing it again.
2. This is actually a separate issue entirely, but my Up, Down, and Left buttons don't work. Only the right one does. Not entirely sure why.

Any ideas? Did a quick search and haven't found anything about either of these two things. Posting here because Q1 has to do with the Pi Zero
 
E_Chang said:
Hey everyone! First post...

I just finished building two 4.3 HMs (minus the 3 LEDs). I have a lot of experience with building circuits so I'm fairly certain the PCBAs themselves are fine. Bought a Pi Zero, uploaded the files from the Installation guide, booted it up using USB power and the HM atmega looks like it programmed correctly (says no pit probe etc). No issues so far. Wifi dongle even works and shows up on my network.

I remove USB power and power the HM from the barrel plug using a 12v supply I have. Couple seconds later, the PiZero stops responding and it's very hot (definitely fried).

Two questions:
1. Since I did not install the 3 LEDs yet, does this have anything to do with the Pi being destroyed? I took a look at a screenshot of the board layers from a routing program that someone posted but I can't figure it out on my own (ME by trade, not EE). I have another Pi on the way, but ideally i'd like to make sure I know what's up before installing it again.
2. This is actually a separate issue entirely, but my Up, Down, and Left buttons don't work. Only the right one does. Not entirely sure why.

Any ideas? Did a quick search and haven't found anything about either of these two things. Posting here because Q1 has to do with the Pi Zero
Click to expand...
If only your right button works then it's likely your resistors for R2, R9, and R11 are wrong. The BOM had a mistake for those until recently and missed the "k" out.

Verify that you have:
R2: 3k9
R9: 8k2
R11: 1k8
 
I can't think of any reason why the pi zero would get fried unless you somehow managed to have 12v on the pi header on the hm board. Maybe fire up the HM board without the pi attached and take a voltage reading on all of the pins. Other than that, static shock?
 
Yeah I can't think of any reason there would be current passed to a Zero any more than any other Pi. Only thing I can think is that there's 12V getting to the 5V line, or maybe the Rx/Tx or SPI lines are getting more than 3.3V on them? You can test all of those with the Pi disconnected. Just run across the Pi connector on the heatermeter with a multimeter and check for anything above 3.3V, and there should be only two, the 5V pins.
 
Everything I've read about over-volting the GPIO pins ie 5v on a 3.3v pin, says that it will basically kill the ability to use those pins, but the Pi should keep working.
 
Thanks for the input everyone!

PatrickF said:
If only your right button works then it's likely your resistors for R2, R9, and R11 are wrong. The BOM had a mistake for those until recently and missed the "k" out.

Verify that you have:
R2: 3k9
R9: 8k2
R11: 1k8
Click to expand...

Ah that explains it. I just bought the mouser project that was posted on Github. Guess the change was within the last week or two?

Steve_M said:
I can't think of any reason why the pi zero would get fried unless you somehow managed to have 12v on the pi header on the hm board. Maybe fire up the HM board without the pi attached and take a voltage reading on all of the pins. Other than that, static shock?
Click to expand...
Steve_M said:
Everything I've read about over-volting the GPIO pins ie 5v on a 3.3v pin, says that it will basically kill the ability to use those pins, but the Pi should keep working.
Click to expand...

Will do. I figured a PI would have TVS protection but yea, the Pi definitely doesn't work. I'm guessing an internal short. SOC gets super hot and when I plug it into my computer, the usb port fuses trip and the computer says a USB device is trying to draw too much current.

Bryan Mayland said:
Yeah I can't think of any reason there would be current passed to a Zero any more than any other Pi. Only thing I can think is that there's 12V getting to the 5V line, or maybe the Rx/Tx or SPI lines are getting more than 3.3V on them? You can test all of those with the Pi disconnected. Just run across the Pi connector on the heatermeter with a multimeter and check for anything above 3.3V, and there should be only two, the 5V pins.
Click to expand...

Will do.
 
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So, I swapped out the resistors and now the buttons work. Still need to probe the pins for the Pi to see if there are issues there.
 
So, my second replacement Pi Zero also got fried. Probed the pins on the HM and confirmed correct voltage on all the v+ lines.

Pi Zero worked well for awhile but fried again after plugging it in. Not sure what fries it or what to do but it's obviously very frustrating.

The only thing I can think of right now is to throw in some small switching regulators I have to power the pi separately (while leaving all the data pins still connected to the HM). That should be able to filter out any voltage spikes during plug/unplug.

Any thoughts?
 
How are you powering it? If you've got USB power connected to the Zero and also have the 12v plug powering the HM, that will most certainly damage the Zero. Other than that, there should be no reason why the Zero is failing when connected to a proper made HM board.
 
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