RobG 1,891 Posted November 10, 2011 Share Posted November 10, 2011 The MCU is MSP430G2xx3 and the display is Nokia 5110. The project is not finalized, I will add schematic and board later on. Here are the specs: Number of channels: 2 Reference: internal or external (space for optional Maxim's, Linear's, and TI's Vrefs.) Input protection. Optional shunt resistor. Host connection: SPI, UART (optional RS232.) Optional resistor divider and multi turn pot. Two general use outputs/inputs Two switches Board size: 45mm x 45mm (50mm with optional switches and LEDs,) matches 5110 footprint. Little background. My original panel meter was designed to fit behind 4 digit 0.56" LED display. Then I figured it will be better to use 16x2 LCD which will let me display more information. Now, after playing around with 5110, I decided that this display is the perfect choice for me since nothing beats nice GUI. thanhtran, zeke, dzsombor96 and 1 other 4 Quote Link to post Share on other sites
bluehash 1,581 Posted November 13, 2011 Share Posted November 13, 2011 Does number of channel mean ADC channels? Quote Link to post Share on other sites
RobG 1,891 Posted December 20, 2011 Author Share Posted December 20, 2011 The code is still not 100% finished (data logging via RS232 part,) but the UPM is pretty much fully functional. Because I am using headers to plug LCD, the spacers are 0.5". Normally, LCD would be soldered and the space between LCD and the board would be 0.25". bluehash 1 Quote Link to post Share on other sites
bluehash 1,581 Posted December 20, 2011 Share Posted December 20, 2011 Awesome... What font are the numbers? Quote Link to post Share on other sites
RobG 1,891 Posted December 20, 2011 Author Share Posted December 20, 2011 I have created my own 10x14 font. It's not the full set, just the numbers, letters, and signs I need. Quote Link to post Share on other sites
zeke 693 Posted December 20, 2011 Share Posted December 20, 2011 I like this. Good job Rob! Where did you get the LCD from? Sparkfun, iteadstudio or ebay? Quote Link to post Share on other sites
timotet 44 Posted December 20, 2011 Share Posted December 20, 2011 great work rob Quote Link to post Share on other sites
RobG 1,891 Posted December 20, 2011 Author Share Posted December 20, 2011 I like this. Good job Rob! Where did you get the LCD from? Sparkfun, iteadstudio or ebay? That one is from iTead, but I also have some from eBay. Quote Link to post Share on other sites
timotet 44 Posted December 21, 2011 Share Posted December 21, 2011 Just curious, what is the small row of holes across the bottom of your PCB for? Quote Link to post Share on other sites
RobG 1,891 Posted December 21, 2011 Author Share Posted December 21, 2011 The holes make it easier to cut the board. If you don't need LEDs and switches that are in the front (you can mount them on the other side by the way) you can just cut that piece of and make your board exactly 45mm x 45mm, which is the size of 5110. Quote Link to post Share on other sites
timotet 44 Posted December 21, 2011 Share Posted December 21, 2011 thats what I though they were for thanks Quote Link to post Share on other sites
username 198 Posted December 22, 2011 Share Posted December 22, 2011 Nice! I like the display. So voltage only? Is it auto ranging? i'd be sweet if you could do current, connectivity, and ohms. Be pretty sweet to make a msp430 multimeter! Quote Link to post Share on other sites
RobG 1,891 Posted December 22, 2011 Author Share Posted December 22, 2011 It can do current (as pictured) using shunt resistor, but no auto-ranging. Quote Link to post Share on other sites
username 198 Posted December 23, 2011 Share Posted December 23, 2011 It can do current (as pictured) using shunt resistor, but no auto-ranging. sorry, was being blind. Anyhow! Super cool concept and theres still alot you can build off this. I really wanted to make something like this at some point. I only got a 10year old radio shack multimeter so a replacement is needed. Thanks for sharing Any chance you would be willing to share project code for newbsauce like me? Quote Link to post Share on other sites
calin 4 Posted December 23, 2011 Share Posted December 23, 2011 Nice project ... I like it. I was playing with something similar for a bench power supply I am building. I have one question. While working on my meter I noticed that the ADC on the MSP430 has an habit of influencing the "measured" circuit with its impedance. For example in my case a simple voltage divider that brings 0-20V to 0-3.3V is influenced by the ADC input impedance in quite nasty ways. I do not see anything special in the input channel circuits you have in the schematics that would deal with this issue. Or am I missing something obvious as a novice that I am ? Quote Link to post Share on other sites
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