Sun Sep 03, 2017 12:52 pm
Some thoughts on Barbouri’s OpenEVSE board ver 4.2. The source was available earlier and the board works for me. I think the current version is 4.23. All of his designs are Descrete vs Chris,s SMD design. I am an old fossil and I like repairable vs throw away
First the regulator IC is no longer available from Digikey so you may have to use my descrete 78L05 mod. Before it was was very expensive.
The most expensive chip on the board is the mid400 at nearly $5. It is now second sourced from China for less than $1. I was using 6N139’s but at this price why not use the real thing.
I use 47K 1/2W thin film resistors vs the original 28K’s. The board has a space for fuses for carbon resistors and I put in 1N4004’s instead since current firmware requires half wave sensing. It makes a good spot for the diodes. You can also use 1N4148 shunt diodes across the input but the fuse spaces are neater
The current board uses Nick Sayer’s GFCI test. It turns out that that is the same as RLY2 on the board. You just need 2 connectors and a 2 pin header at RLY2. The resistor value is the same.
There is no standard for the I2C pins and Chris has them swapped vs Barbouri so if you use a stock OpenEVSE display you need to swap the wires.
I do not populate the other resistors or headers since I do not use them.
Barbouri has gone hog wild with bypass caps but since the holes are there I use them. 1 chip caps are less than a nickel on eBay so it hardly adds an expense.
I use both Chris’s DIY ver 2 and Barbouri’s ver 4.2 boards. Both work well but Barbouri’s output is more elegant. With Chris’s boards I add 1N4148 shunt diodes to the mid400 inputs. Since the most voltage they ever see is the 3V LED they work well.
2012 Cayenne Red SL traded for:
2013 Pearl White SL Premium
Traded for a Cirrus White 2014 Mercedes B (totaled)
2016 Urano Gray eGolf SEL w/ drive assist
Loved the VW but it sat too low for my old body
Back to a Cirrus White 2017 B250e