Hi. I have been working through the emonGLCD build, but when I measure the voltage at step 16, I do not get 3.3 volts. I get less than one volt. I thought that this could be due to a faulty voltage regulator. With a multi-meter's positive on the topmost leg of the voltage regulator, I get 5.3 volts with the negative on one of the bottom legs, and 3.17 volts if I move the negative to the other leg. Therefore I assume the regulator is working okay. What should I test next?
I've not built this circuit myself, but when measuring DC voltage I think you may do best to leave the negative lead attached to the OV rail, and just move the positive lead around.
Your voltage regulator may be working fine but is being prevented from doing its job because of some other fault ...
I'm not sure where you're measuring the power between but you should read 3.3V between GND and 3V pads on and 5V between PWR and GND pads. Look for those labels on the PCB. 3.17V sounds a little low for nothing connected. Am I correct in assuming you don't have the micro-processor chips in the socket nor the RF module or LCD fitted?
Thanks for the unexpected late night responses! I have some specific observations: 5.18v between GND and PWR on JeePort. 5.18v between JeePort GND and middle leg (topmost) on the voltage regulator. 2.02v between JeePort GND and right-most leg of the voltage regulator. Approx. 1v steadily dropping away between GND and VCC of RFM12B pads. Note that I am describing positions viewing the PCB from the front, with the Welsh dragon visible.
Perhaps there is a problem with the voltage regulator, and possibly a capacitor? The voltage dropping away is presumably a capacitor discharging.
Glyn, you are correct. The chip is not on the board (although the socket is). The three switches have not been fitted, nor the RF module, attaena, backlight or LCD display. The PCB is version 1.3.
Thanks for your help.
It does sound like you might have a faulty regulator. Please order a replacement from the shop: http://shop.openenergymonitor.com/nanoderf-mcp1702-voltage-regulator-rep...
I'm assuming you have double checked the orientation of the regor and polarity of the capacitors
Yeah. I'll see if a new voltage regulator does the trick. Cheers Glyn.
Open-source tools for energy monitoring and analysis. This project uses the GNU General Public Licence