Vidmo

LIR batteries are rechargable, CR aren't. They look the same and provide similar voltage. Keep that in mind and do not throw away good batteries.And my second thought is, that there should be some battery protection and optionally charging circuit. You shouldn't over discharge lithium batteries, because this decrease their lifetime a lot.

TI's TLV61220 has Iq=5uA, Vi can be as low as 0,7V, it costs less than $1. I think that is worth considering it.

Awesome watch. I made Atmega328 LED watch myself some time ago. I found disappointing, that even though battery has some juce left, LEDs are dim. So we both were right and wrong about converters. They waste some power, but good ones allow to take more power from batteries. Eg. Atmega328 won't work below 1.5V (I might be wrong, but it's not far from that) red LEDs are barely visible then. With simple modern converter you can supply 3.3V from 0.7V battery with 90% efficiency. For me that's much better than seeing LEDs fade out with battery juce and having bunch of half empty cells...

I'm sorry to inform you that your antenna design is totally wrong. Take a look at this instructable https://www.instructables.com/id/Enhanced-NRF24L01/ NRF24L01 uses the same freq, so antenna should be similar. You can connect yours antenna's shielding to GND and core to HF signal. You have to cut tracks on PCB to do so. ESP has only one antenna transmitter/reciever, thus using two antennas will only make signal transmission worse.

I'm sorry, but I'm not sure what do you mean. If this is question, than ATmega8 is uC and 16pu means 16MHz max clock and DIP package. Thus it's basically good ol' ATmega8 same as I used. Read other comments for more tips.

You are right about supply cap. I should add ~100nF. Logic level MOSFET should be used with 5V circuit, or another BJT as amplifier should be added. I used this circuit with PC fan, so output was connected directly to fan PWM input and I didn't think about that. Pot will draw 5V/100k=50uA, and washer position has nothing to do with that. RC filter is not necessary, it's stable. Zener diode LDO works different than you think. Here's tutorial http://www.electronics-tutorials.ws/diode/diode_7.html . Max current will be 12V/110r=110mA. So 100mA should be safe to draw, because Z-diode needs some current passing through, and 100mA is more than enough for ATtiny driving one PWM and ADC.

I meant that Peltier cooling is not effective enough when achieved device temp. is higher that ambient temp. In that case radiator-fan setup is better. But in your case device temp. is lower than ambient temp. so this chiller is not only dissipating heat but also truly cooling.

Very nice project, I appreciate clean build especially, but I think that peltier is producing more heat energy than is absorbed by it's cool side (it's not ideal device), so it's less effective than fan with radiator only...

Hi, I assume that you want to use analog temperature sensor.I see few mistakes:1. Small ATtinys don't have hardware seria,l so you can use software serial library instead. 2. You define with macro and integer variables with same names. Delete #define ones, because they are constant. Google #define to understand how it works. And never again try to define few variables/constants with same name!I'm not shure why do you map sensor value to 100-255 and then set that to zero when sensor is lower than 450. That might be logical mistake, but I don't know what do you want to do..Try that chip with potentiometer instead sensor. It's simpler and faster.

Rf is reference resistance. Formula is for other connection: sensor (Rs) is connected to GND and Rf, which is connected to 5V.I'm mapping voltages to 10000mV, because I used voltage divider for sensing higher voltages. This simple converter can supply voltages from 0 to Vcc-2.2V, so when 12V is applied It can go up to 9.8V and ATmega won't tolerate that.Both issues are shown on schematic. I tested voltage on sensor and resistance (device powered down just after heating cycle) with multimetr, and they are very close to that Arduino reads. Sensor shows something like 10000-30000ppm in jar where all air was burned out with a lighter. Alarm goes on when ALARM value has been reached and stays on at least for one heating cycle.

how long does it take to discharge that battery?

Didn't see that, sorry for question.

Thanks fot your comment. I assume, that I'll have to find somebody with CO meter for calibration :)As for formula - I assumed that anything higher than 4000ppm is lethal... I just found "manual" for it which gives ppm relation to clean air resistance https://cdn.sparkfun.com/datasheets/Sensors/Biometric/MQ-7%20Ver1.3%20-%20Manual.pdfAnd I'm getting more unsure about this sensor...You might be right about voltages, but I thing I'll check that with scope, just to be sure.Also I'm thinking about cutting traces (I have module similar to yours) and making separate circuits for sensor and heater. I desoldered opamp, so DO pin is free to use as separate supply for heater, this should improve output voltage stability.

try modern approach to this problem: http://playground.arduino.cc/Main/ArduinoOnOtherA...MiniCore includes m8

I forgot about fuses (they keep info aboat bootloader max size, which is reserved for bootloader only), here's updated code:## Arduino Nano w/ ATmega328 w/Optiboot## -------------------------nano.menu.cpu.atmega328opti=ATmega328 optibootnano.menu.cpu.atmega328opti.upload.maximum_size=32256nano.menu.cpu.atmega328opti.upload.maximum_data_size=2048nano.menu.cpu.atmega328opti.upload.speed=115200nano.menu.cpu.atmega328opti.bootloader.low_fuses=0xFFnano.menu.cpu.atmega328opti.bootloader.high_fuses=0xDEnano.menu.cpu.atmega328opti.bootloader.extended_fuses=0xFDnano.menu.cpu.atmega328opti.bootloader.file=optiboot/optiboot_atmega328.hexnano.menu.cpu.atmega328opti.build.mcu=atmega328p

You also have to cange upload speed to 115200. I tried it at home and it works well. On other system boards.txt was in C:\Program Files (x86)\Arduino\hardware\arduino\avr.Heres code for new CPU for Nano board, screenshot shows where to paste it:## Arduino Nano w/ ATmega328 w/Optiboot## -------------------------nano.menu.cpu.atmega328opti=ATmega328 optibootnano.menu.cpu.atmega328opti.upload.maximum_size=32256nano.menu.cpu.atmega328opti.upload.maximum_data_size=2048nano.menu.cpu.atmega328opti.upload.speed=115200nano.menu.cpu.atmega328opti.bootloader.low_fuses=0xFFnano.menu.cpu.atmega328opti.bootloader.high_fuses=0xDAnano.menu.cpu.atmega328opti.bootloader.extended_fuses=0xFDnano.menu.cpu.atmega328opti.bootloader.file=optiboot/optiboot_atmega328.hexnano.menu.cpu.atmega328opti.build.mcu=atme...

You also have to cange upload speed to 115200. I tried it at home and it works well. On other system boards.txt was in C:\Program Files (x86)\Arduino\hardware\arduino\avr.Heres code for new CPU for Nano board, screenshot shows where to paste it:## Arduino Nano w/ ATmega328 w/Optiboot## -------------------------nano.menu.cpu.atmega328opti=ATmega328 optibootnano.menu.cpu.atmega328opti.upload.maximum_size=32256nano.menu.cpu.atmega328opti.upload.maximum_data_size=2048nano.menu.cpu.atmega328opti.upload.speed=115200nano.menu.cpu.atmega328opti.bootloader.low_fuses=0xFFnano.menu.cpu.atmega328opti.bootloader.high_fuses=0xDAnano.menu.cpu.atmega328opti.bootloader.extended_fuses=0xFDnano.menu.cpu.atmega328opti.bootloader.file=optiboot/optiboot_atmega328.hexnano.menu.cpu.atmega328opti.build.mcu=atmega328p

What version of IDE are you using?Also paste here what IDE says whan you enable verbose output (file > preferences > show verbose output during: check both compilation and upload).Or you may try simple way: http://playground.arduino.cc/Main/ArduinoOnOtherAt...MiniCore has ATmega8 with optiboot implemented.

Just remember: do not mess with fuses, unless you know what you change. Fuses keep info about clock source, memory access, etc. Wrong selection may brick uC.I used that method to burn Optinoot to ATmega328P-AU (Nano's uC), but it used different xtal: 4MHz, so fuses was different. This way it works on single CR2032 3V battery. uC dies when voltage goes lower than approx. 1.6V.If you want to change fuses for eg. Different clock xtal and different minimum volrage called BOD level you can use some online AVR fuses calculators. They should have fuses description, which allow to understand what fuses do.

You should be able to burn optiboot just by changing code in boards.txt http://playground.arduino.cc/Main/CustomizeArduino...Just copy upload.maximum_size and bootloader.file path from Uno and paste to Nano and burn bootlaoder with another Arduino as ISP or other AVR programmer.

You may try using lasergrbl.com instead of my software. It seems to be good equivalent.

Try two things: change files in new IDE's locations:C:\Users\YourPrfile\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.15and this version of board for boards.txt (It's based on new IDE, you have to select board and cpu)###############################################################atmegang.name=ATmega8 optibootm8o.upload.tool=avrdude1m8o.upload.protocol=arduinom8o.upload.speed=19200m8o.bootloader.tool=avrdude1m8o.bootloader.unlock_bits=0x3Fm8o.bootloader.lock_bits=0x0Fm8o.build.mcu=m8om8o.build.f_cpu=16000000Lm8o.build.board=AVR_NGm8o.build.core=arduinom8o.build.variant=standard## ATmega8 optiboot CPU## ------------------------------m8o.menu.cpu.atmega8=ATmega8m8o.menu.cpu.atmega8.upload.maximum_size=7168m8o.menu.cpu.atmega8.upload.maximum_data_size=1024m8o.menu.cpu.atmega8.b...

Try two things: change files in new IDE's locations:C:\Users\YourPrfile\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.15and this version of board for boards.txt (It's based on new IDE, you have to select board and cpu)###############################################################atmegang.name=ATmega8 optibootm8o.upload.tool=avrdude1m8o.upload.protocol=arduinom8o.upload.speed=19200m8o.bootloader.tool=avrdude1m8o.bootloader.unlock_bits=0x3Fm8o.bootloader.lock_bits=0x0Fm8o.build.mcu=m8om8o.build.f_cpu=16000000Lm8o.build.board=AVR_NGm8o.build.core=arduinom8o.build.variant=standard## ATmega8 optiboot CPU## ------------------------------m8o.menu.cpu.atmega8=ATmega8m8o.menu.cpu.atmega8.upload.maximum_size=7168m8o.menu.cpu.atmega8.upload.maximum_data_size=1024m8o.menu.cpu.atmega8.bootloader.low_fuses=0xbfm8o.menu.cpu.atmega8.bootloader.high_fuses=0xdcm8o.menu.cpu.atmega8.bootloader.file=optiboot/optiboot_atmega8.hexm8o.menu.cpu.atmega8.build.mcu=atmega8##############################################################

That is some issue with file format. Color map is not recognizable by program. Maybe it shouldn't be BW. I lost code and I don't remember exactly what was there... Try saving it in different format.