Comments on: SAE J1772 EV charger checker

By: Jeroen Meijer

Jeroen Meijer — Wed, 29 Jun 2016 11:00:44 +0000

In reply to Andy Fraser. I'd think the only logical conclusion is then that the car takes less than it should, UNLESS the current that you report the car is taking is being calculated the RMS power divided by the voltage. The cos phi is a real thing at these lower rates.

By: Andy Fraser

Andy Fraser — Wed, 29 Jun 2016 08:24:57 +0000

In reply to Jeroen Meijer. Yes, the bug confirms 12A; car takes 10A.

By: Jeroen Meijer

Jeroen Meijer — Tue, 28 Jun 2016 10:29:50 +0000

In reply to Andy Fraser. Thank you! Fixed

By: Jeroen Meijer

Jeroen Meijer — Tue, 28 Jun 2016 10:29:07 +0000

In reply to Andy Fraser. It indicates in fact the copper diameter translated to amps. You need to multiply by 3 for 3 phases indeed! The car ony knows there are 3 phases because, well, it gets fed 3 phases. There is noting in the protocol. Does the bug tell you you 12A too? My commercial chargebox is set to 16, bug says 15, car takes 15-and-a-bit.

By: Andy Fraser

Andy Fraser — Tue, 28 Jun 2016 09:48:28 +0000

Line 42 of the sketch should read – Check the code for “ATmega328”

By: Andy Fraser

Andy Fraser — Tue, 28 Jun 2016 07:43:41 +0000

Have you tried it with a 3-phase charger? I wondered if it would indicate the total, or per phase current.

Although my granny lead is set to 12A, my ZOE only seems to take 10A – perhaps this is because it’s an early model (October 2013).

By: Jeroen Meijer

Jeroen Meijer — Mon, 27 Jun 2016 17:07:39 +0000

In reply to Andy Fraser. Hehe, well, I will change that then. The ATtiny85 is default fused @ 1Mhz, therefor the warning. Precision is good at 8 MHz; 16 will NOT be a problem. Thanks for letting me know it works and enjoy the little bugger :-)

By: Andy Fraser

Andy Fraser — Mon, 27 Jun 2016 16:18:45 +0000

I built it today and I can confirm that it works perfectly with an ATmega168 (5v, 16Mhz) Pro-Mini. I was a little concerned where it said “Careful, 8 MHz needed!” at the top of the listing, but it was no problem.

I tested my home-made granny cable (12A) and my supplied home charger (30A).

By: Andy Fraser

Andy Fraser — Sat, 25 Jun 2016 10:41:13 +0000

Thanks Jeroen. I won’t get chance to build it until next week. I’ll let you know how I get on. I’ll probably use the Pro-Mini’s own LED.

By: Jeroen Meijer

Jeroen Meijer — Sat, 25 Jun 2016 10:02:40 +0000

In reply to Jeroen Meijer. Done, you can pick up the source on codebender and change the lines where a reference to the 328 is made. Let me know if it works please Andy, I haven no chance to test it on a 328 anywhere soon.