Hiho,
Yesterday when I started my 5 year old HMv4.2 it reported a pit temp of 670 when the fire was cold (32ish in New Hampshire). Today I pulled the board to experiment.
3.3v power is good. Food probe 3 is at 2.5v when connected to a minijack probe at 69 degrees F. The HM reports that probe at 105.7 degrees F. That reading rises to 120F when I hold the probe tip. A Thermoworks J-Type probe which is known to work on a thermoworks sensor is causing .1V output from the AD849x at 20 degrees C. The AD849x data sheet says that is correct. The HM reading is 658 degrees F. If I hold the probe tip the HM reading falls to 620F (wierd). The computer, webpage and USB wifi all appear to be working normally.
It sounds like the A/D conversion is broken. Do you have any suggestions on how I could confirm that? Is it possible that the ATMega328P failed? I tried removing it from the socket and reinserting it, but the problem persist. Thanks in advance for any advice you can provide to me.
Web
Yesterday when I started my 5 year old HMv4.2 it reported a pit temp of 670 when the fire was cold (32ish in New Hampshire). Today I pulled the board to experiment.
3.3v power is good. Food probe 3 is at 2.5v when connected to a minijack probe at 69 degrees F. The HM reports that probe at 105.7 degrees F. That reading rises to 120F when I hold the probe tip. A Thermoworks J-Type probe which is known to work on a thermoworks sensor is causing .1V output from the AD849x at 20 degrees C. The AD849x data sheet says that is correct. The HM reading is 658 degrees F. If I hold the probe tip the HM reading falls to 620F (wierd). The computer, webpage and USB wifi all appear to be working normally.
It sounds like the A/D conversion is broken. Do you have any suggestions on how I could confirm that? Is it possible that the ATMega328P failed? I tried removing it from the socket and reinserting it, but the problem persist. Thanks in advance for any advice you can provide to me.
Web