KrisKasprzak
Well-known member
First,
I’ll have to continue my thanks to the guru’s on this forum for all you help ad advice.
I have a question regarding AREF with my Teensy 3.2. My project is powered with a 24VDC battery that runs through a buck converter. I have a voltage divider to read 24 VDC, a thermistor and transceiver (amongst a few other things). My transceiver E50-TTL-500 draws almost no power at idle, and draws only when sending. I send 50 bytes every second and due to the power draw from the E50, I see a fluctuation in buck converter output which effects the thermistor reading (temp briefly rises or falls—I can’t remember). Even my voltage reading circuit fluctuates. See attached image of a block diagram and simple graph of the signal vs Vcc.
I’ve tried caps on the power supply side (like up to 6000 MFD) to buffer the supply voltage but I still have a power draw issue. I've tried several other buck converters to no avail. i'm pretty sure it's the instant power up from the E50. My current hack is to delay several hundred ms after transmit to let Vcc recover--it work but feels like amateur hour
So…
My wild idea is to connect my 3.3 volt supply from the buck converter to VREF, any changes in supply voltage will be compensated by VREF. Of course add the line analogReference(EXTERNAL); early in setup().
1. Would this be a correct usage of VREF
2. Will it help?
I can try, but since I’ve never used VREF, I don’t want to damage my precious Teensy 3.2
I’ll have to continue my thanks to the guru’s on this forum for all you help ad advice.
I have a question regarding AREF with my Teensy 3.2. My project is powered with a 24VDC battery that runs through a buck converter. I have a voltage divider to read 24 VDC, a thermistor and transceiver (amongst a few other things). My transceiver E50-TTL-500 draws almost no power at idle, and draws only when sending. I send 50 bytes every second and due to the power draw from the E50, I see a fluctuation in buck converter output which effects the thermistor reading (temp briefly rises or falls—I can’t remember). Even my voltage reading circuit fluctuates. See attached image of a block diagram and simple graph of the signal vs Vcc.
I’ve tried caps on the power supply side (like up to 6000 MFD) to buffer the supply voltage but I still have a power draw issue. I've tried several other buck converters to no avail. i'm pretty sure it's the instant power up from the E50. My current hack is to delay several hundred ms after transmit to let Vcc recover--it work but feels like amateur hour
So…
My wild idea is to connect my 3.3 volt supply from the buck converter to VREF, any changes in supply voltage will be compensated by VREF. Of course add the line analogReference(EXTERNAL); early in setup().
1. Would this be a correct usage of VREF
2. Will it help?
I can try, but since I’ve never used VREF, I don’t want to damage my precious Teensy 3.2
