Still in development, so specs and features presented here are not final!
USB-C Amp Meter Mk2
Bringing the (good old) amp meter to new levels:
- higher resolution: 20bit analog digital converter (versus 16 on the original) enables 20µA measurement resolution
- higher currents: that higher dac resolution also raises current limit to 15A (peak), plenty
of headroom to power those PC gaming laptops.
As the pcb is still being designed, I have not finally decided on the maximum permanent current the meter can handle! - energy/charge: the new chip used also features energy and charge meters
- not limited to USB-C: the new PCB features additional power connectors with looped id pin support, so you can finally connect like Dell power supplies and laptops
- new power design: the new power design enables standalone usage, while the first version was
solely powered through the usb data connection.
Additional circuitry prevents startup delays even in standalone mode (for instance when a PD charger is turned off when disconnected, like Apple's)
Other notable changes:
- improved form factor: v1 was more like an electronic design study, and featured an esp8266
development board.
The new variant implements the microcontroller directly on the board, reducing the device's thickness - more accurate measurement due to improved noise-cancelling on the current shunt
This (of course) comes with a few drawbacks:
- I had to drop serial protocol compatibility with PLD's meter.
The enhanced resolution and additional measurements did just not fit in neither the data format (9 bytes) nor the baud rate (9600 previously).
This also means you have to use my OSD software (or roll your own). - higher price point: the new power measuring chip is twice as expensive as the old one, the
esp8266's development board parts are way more expensive than the dev board, and all the additional
power circuitry adds up. Plus I may need thicker copper on the pcb to account for the higher
current.
While the first version's components were less than 10 €, it seems version 2 is more like 25-30€ (only parts, no labour, no allocation of design costs).
I'm still undecided if I go for a larger display. Also I'm not proficient in 3d design, so there's still no decision on having a 3d printed case.
I'm looking for people interested in the new power meter, so I can order the second set of pcbs and
components accordingly. Please drop me an
email if you are interested in acquiring the meter, and I'll keep you updated on the
progress.
Once version 2.0 is considered stable and good to go, there will be some shop link here and in your
inbox.