Hairy Animal
Member
I'm intending to use a 20M2 to read the position of mechanical throttle control lever using optical sensors and, having sensed the position, convert that to a (nominal) 0V to +5V analog output to control the speed of the 72V 20kW motor driving our 40' boat via the electronic controller (which has a 0 - 5V input). Needless to say, this is a safety critical application so I want it to be safe & reliable above all else!
On p.53 of the picaxe_manual2 the description of the DACSETUP command recommends an op-amp buffer which seems very sensible, together with a 100nF capacitor, presumably to smooth the output. That all looks fine until noting that the DAC output (on the 20M2, 14M2 & 8M2) is the same pin as Serial Out, used for programming the device. Presumably, this much capacitance on the pin will interfere with programming?
Is the best option to fit a jumper between the 100nF and the pin and remove it for programming? Or does anyone have a better suggestion?
Thanks in advance for all help.
Charles (retired electronic engineer, now boat restorer)
On p.53 of the picaxe_manual2 the description of the DACSETUP command recommends an op-amp buffer which seems very sensible, together with a 100nF capacitor, presumably to smooth the output. That all looks fine until noting that the DAC output (on the 20M2, 14M2 & 8M2) is the same pin as Serial Out, used for programming the device. Presumably, this much capacitance on the pin will interfere with programming?
Is the best option to fit a jumper between the 100nF and the pin and remove it for programming? Or does anyone have a better suggestion?
Thanks in advance for all help.
Charles (retired electronic engineer, now boat restorer)