E-MotorWerks JuiceBox - an open source 15kW EVSE

[dsinned]

Any method of adjusting the pilot to set the max current works. You spent a great deal of money on your JuiceBox and you are proud of it. Any OpenEVSE with a display and select button can also set the current. The stock table goes by 5A steps from 10A to 80A. I edit it from 10A to 50A in 2 A steps. It could have 1A steps but that becomes cumbersome.

Correct! However, I did spend a whole lot more (~$1500) for a Leviton L2 EVSE and before that (~$800) for an SPX L2 EVSE, neither of which were nearly as versatile as my JuiceBox. There was no way whatsoever to adjust/limit current my Leviton and the SPX's "adjuster" was virtually inaccessible. Thus, those EVSEs essentially only had fixed outputs of 32a and 24a respectively, except when charging my VOLT that only allowed 15a max. All three EVSEs were "plug ins", but I still have to give the nod to JuiceBox for being the most portable and easiest to transport.

I dabbled with a few customizations to my Leviton (i.e. adding a dual AC V/A display module), but went all out on my JuiceBox. I had no clue how to modify the electronics in the Leviton or SPX, but was able to modify the firmware in my Juicebox. This allowed me to implement a fully customized display capability and some additional upgrades to support enhancements to the existing AC voltage and current measurements as well as adding an internal MCU based temperature monitor.

I have since made various AC input adapters for my JuiceBox, so that its overall portable versatility will be even better.

Was my JuiceBox worth the total cost of ~$700? ABSOLUTELY!!!

[GlennD]

Any method of adjusting the pilot to set the max current works. You spent a great deal of money on your JuiceBox and you are proud of it. Any OpenEVSE with a display and select button can also set the current. The stock table goes by 5A steps from 10A to 80A. I edit it from 10A to 50A in 2 A steps. It could have 1A steps but that becomes cumbersome.

Correct! However, I did spend a whole lot more (~$1500) for a Leviton L2 EVSE and before that (~$800) for an SPX L2 EVSE, neither of which were nearly as versatile as my JuiceBox. There was no way whatsoever to adjust/limit current my Leviton and the SPX's "adjuster" was virtually inaccessible. Thus, those EVSEs essentially only had fixed outputs of 32a and 24a respectively, except when charging my VOLT that only allowed 15a max. All three EVSEs were "plug ins", but I still have to give the nod to JuiceBox for being the most portable and easiest to transport.

I dabbled with a few customizations to my Leviton (i.e. adding a dual AC V/A display module), but went all out on my JuiceBox. I had no clue how to modify the electronics in the Leviton or SPX, but was able to modify the firmware in my Juicebox. This allowed me to implement a fully customized display capability and some additional upgrades to support enhancements to the existing AC voltage and current measurements as well as adding an internal MCU based temperature monitor.

I have since made various AC input adapters for my JuiceBox, so that its overall portable versatility will be even better.

Was my JuiceBox worth the total cost of ~$700? ABSOLUTELY!!!

The beauty of open source is that everything is documented and you were able to mod your unit. Most of the EVSEs that I build sell for around half of that. The main thing is that you are happy with your unit!

My first EVSE was a Leviton 16 unit I paid $1000 less the fed 30%. I discovered the OpenEVSE project and recovered my costs for the Leviton.

Over the years it has evolved. I started with a basic board. Then GFCI was added, A display and select button came along, then the advanced power module came about, Nick Sayer added a GFCI routine and current measurement to the display. Goldserve coded in the RTC for his own use and then made it public. The beauty of open source is that many add enhancements.

No group is going to add enhancements to the Leviton or Clipper Creek EVSEs. The manufacturer has to see a possible return for each mod.

[dbg]

Hi, all,
Where to get this firmware 8.7.13b? Do we have an open source repository for it somewhere?

I have a 8.7 base board and extra parts from EWM this March and got the premium features installed last week, finally. Everything works under reprogrammed FW v8.7.9 (fig.1). I found a few minor things to fix and might want to work on it when I have time:)

My first MOD here (fig.2): the exposed USB port and switch that extends the 5V jumper on the FTDI programming card inside the box with an unused 3way switch outside. I can reprogram the board without opening the box any more. Decoupling the risk of exposure to 240V circuitry.

Valery is the expert here, so you should follow his recommendations, but I believe you will still need the FTDI Programming Cable if all you want is to upload a newer version of the firmware. However, "if" your JuiceBox was built with an older version of F/W, you just can't skip to a newer version unless your hardware (PCB version) is KNOWN TO SUPPORT IT. There are certain dependencies in the hardware, that ONLY the same version of firmware supports properly.

For example, I started out with V8.7.9 firmware with a V8.7 PCB. I have since uploaded to F/W V8.7.13b. The latter has various modifications of my own choosing to support a slightly larger display module, but my modified firmware is still based on V8.7.9 (compatible with the original uLCD) and original V8.7.x PCB. Because my PCB is still the same, later version(s) of firmware (e.g. V8.9.1) would NOT necessarily be compatible with my existing hardware, and for sure it wouldn't be 100% compatible with my new display.

Sometimes, new versions of F/W can be made "compatible" with respect to older H/W, but eMW's verification "testing" probably was only done with the latest hardware, so mismatching versions of H/W and F/W would generally not be advisable.

[dsinned]

Nice job dbg! Your uLCD mod is how eMW conceived doing it as well. Unfortunately, making a rectangular cutout in the back of the enclosure is surely a lot of extra work. My approach was to replace the front cover plate with plexiglass and make the uLCD viewable from inside the front of the enclosure. I can't say it was any less work, but it maintains the integrity of the enclosure since I did not have to make any cutouts.

V8.7.13b of the firmware was a version of my own making to support a different 3D Systems 1.7" uOLED display. I've shared it with eMW and commented the source code where revisions were made. However, as to your question about a "repository", unfortunately, I don't believe one yet exists.

JuiceBox firmware is up to V8.10.2 now, but I do not know what changed since V8.9. V8.9 changed the new V8.9 PCB hardware, which incorporated a low wattage, resistive "heater" to guard against freezing climates, and a zero drift OpAmp to resolve GFCI calibration difficulties. Also, the PCB was upgraded to use 1% resistors for higher precision voltage and current measurements.

Good luck with any future modifications to your JuiceBox Basic.

[dbg]

Nice job dbg! Your uLCD mod is how eMW conceived doing it as well. Unfortunately, making a rectangular cutout in the back of the enclosure is surely a lot of extra work. My approach was to replace the cover plate with plexiglass and make the uLCD viewable inside the enclosure while viewing it from the front. I can't say it was any less work, but maintain the integrity of the enclosure somewhat better since I did not have to make any cutouts.

V8.9.13b of the firmware was a version of my own making to support a different 3D Systems 1.7" uOLED display. I've shared it with eMW and commented the source code where revisions were made. However, to your point of a "repository", unfortunately, I don't believe one yet exists.

JuiceBox firmware is up to V8.10.2 now, but I do not know what has changed. I do know about V8.9 of the PCB hardware, which incorporated a low wattage, resistive "heater" to guard against freezing climates, and a zero drift OpAmp to resolved GFCI calibration difficulties. The PCBA also was upgraded to use 1% resistors for higher precision voltage and current measurements.

Good luck with any future modifications to your JuiceBox Basic.

Thanks for all information!
Currently I might stay AS IS.
Down the road, I am thinking to make this Juicebox controllable via wifi/internet.

[cayblood]

I just bought a juicebox premium and would very much like to be able to write scripts to control it via wifi. Do you have any tips on how to get started with this? I'm an experienced software engineer so you can get technical in your explanations.

Thanks,
Carl

[Graplr]

Ok guys. I have finally gotten around to trying to fix my abnormal state issue as I first posted about here on page 23 and 24 of this thread. I am trying to follow Val's (and other's) help.

I have everything connected and am in Arduino. I found the line Val told me to change. I changed it. Then what do I do? I assume I need to save it or upload it somehow. So I click on Verify or Upload. It starts checking everything and comes up with an error on line 359 which is nothing I changed. I copied and pasted the error here-
This report would have more information with
"Show verbose output during compilation"
enabled in File > Preferences.
Arduino: 1.0.6 (Windows 7), Board: "Arduino Uno"
EMW_EVSE_firmware_V8_7_9.ino:70:30: error: EEPROM_VMcharger.h: No such file or directory
EMW_EVSE_firmware_V8_7_9.ino: In function 'void setup()':
EMW_EVSE_firmware_V8_7_9:359: error: 'EEPROM_readAnything' was not declared in this scope
EMW_EVSE_firmware_V8_7_9:410: error: 'EEPROM_writeAnything' was not declared in this scope
EMW_EVSE_firmware_V8_7_9.ino: In function 'void loop()':
EMW_EVSE_firmware_V8_7_9:531: error: 'EEPROM_writeAnything' was not declared in this scope
EMW_EVSE_firmware_V8_7_9:619: error: 'EEPROM_readAnything' was not declared in this scope
EMW_EVSE_firmware_V8_7_9.ino: In function 'void ctrlMenu()':
EMW_EVSE_firmware_V8_7_9 error: 'EEPROM_writeAnything' was not declared in this scope
EMW_EVSE_firmware_V8_7_9 error: 'EEPROM_writeAnything' was not declared in this scope

Is this because I have some sort of error in my folder set up? Please forgive me, I am not too familiar with changing code. I can diagnose and work on cars all day mechanically though.

Help please?
Thanks!
Ryan

[Graplr]

I'm getting a bit frustrated with emotorwerks. I have not heard a response in almost 2 weeks now.

[valerun]

I'm getting a bit frustrated with emotorwerks. I have not heard a response in almost 2 weeks now.

sorry about that, Graplr. I will check on why we did not respond.

the answer to your immediate question is easy - you need to have that file in your sketch folder. That file has functions that operate on EEPROM to store / retrieve all config and energy data.

You can get one from any of the zip files in our Firmware web folder. That file did not change from the initial release at all so you are safe grabbing it from any version zip.

Thanks,
Val

[brinkhamer]

4. PCB heater. Yes, we have added a small 6-watt heating element to the bottom of the PCB. It would turn on below 0 degrees F and turn off once the processor core heats above that temperature. This will result in more reliable operation in extremely low temperatures (we did NOT receive any complaints from our customers in Canada / midwest even with a previous version so this is mostly a preventive measure)

FYI, you've got one now, I have cold weather issues and the $0.09 cent difference between a crystal and the ceramic oscillator on the pro-mini is the primary suspect. Ideally I'd rather pay the $0.09 upfront than every 5 days in a heater ideally, thats another $7/year operating cost for a 6watt heater.

(note, did not have problems compiling the source code, though arduino environment changes so fast and is thus by definition unstable, I don't know if I care).