chris stevens
Software to drive a monitor unit for a closed circuit rebreather using 3 electrogalvanic oxygen sensor cells run through an amplifier (lm324) . Uses a separate ds1307 clock IC to get timestamp values for logged data.
Dependencies: DS1307 TextOLED_custom mbed
The main electornics is housed in another pod mounted on the back of the unit. I'm using an mbed lpc11u24 to drive everything which comes with a flash drive for data logging built in. It has an external ds1307 clock chip added and a very cheapo lm324 quad op-amp to amplify the o2 sensor signals from the 10s of mV range by 30x so that ppo2=0.21 corresponds to about 0.3V. I still have to do some ADC averaging with this amplifier and do have to calibrate out the individual offsets of the chip but this works ok now that I've worked out which amp is on which adc...
History
published version of the rebreather monitor software
2013-01-16, by pegcjs [Wed, 16 Jan 2013 13:47:34 +0000] rev 9
published version of the rebreather monitor software
added store_log();in start of dive routine to make a first data point close to surface
2013-01-14, by pegcjs [Mon, 14 Jan 2013 12:55:05 +0000] rev 8
added store_log();in start of dive routine to make a first data point close to surface
Fixed bug in setswitch prevennting switch back to lowsetpoint on ascent; added hud flashes 4 flashes = going to high sp , 2 flashes = going to low sp.
2013-01-14, by pegcjs [Mon, 14 Jan 2013 12:52:45 +0000] rev 7
Fixed bug in setswitch prevennting switch back to lowsetpoint on ascent; added hud flashes 4 flashes = going to high sp , 2 flashes = going to low sp.
finalised version - ready to build permanent hardware
2012-08-07, by pegcjs [Tue, 07 Aug 2012 16:25:18 +0000] rev 6
finalised version - ready to build permanent hardware
basic function done - still no recovery of values fro cal file...
2012-08-07, by pegcjs [Tue, 07 Aug 2012 11:33:03 +0000] rev 5
basic function done - still no recovery of values fro cal file...
leds done bu need to sort out logging data and the recall of saved settings and scrub time in case of swirtchoff between dives on same scrubber.
2012-08-03, by pegcjs [Fri, 03 Aug 2012 14:19:44 +0000] rev 4
leds done bu need to sort out logging data and the recall of saved settings and scrub time in case of swirtchoff between dives on same scrubber.
just leds to go
2012-08-03, by pegcjs [Fri, 03 Aug 2012 11:29:30 +0000] rev 3
just leds to go
basic functions implemented - no backup readout for cal values or any logging. no leds or warnings setup.; need to restrict fo2 to avoid >100% issue and prevent negative depths...
2012-08-02, by pegcjs [Thu, 02 Aug 2012 16:05:46 +0000] rev 2
basic functions implemented - no backup readout for cal values or any logging. no leds or warnings setup.; need to restrict fo2 to avoid >100% issue and prevent negative depths...
barebones in place - max and min functions just added along wtih readsesnors display etc
2012-08-02, by pegcjs [Thu, 02 Aug 2012 14:55:08 +0000] rev 1
barebones in place - max and min functions just added along wtih readsesnors display etc
just started writing
2012-08-01, by pegcjs [Wed, 01 Aug 2012 15:04:18 +0000] rev 0
just started writing