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Post by jrichardson1234 on Mar 5, 2018 8:53:19 GMT -8
Tried to use the 555 watchdog timer with the USB power switcher over the weekend to keep my Particle Photon based weather station alive.
Here is what I have found:
1) Integrate 555 timer based watchdog with USB power switch so its a plug+play with a single Grove cable.
1a) Make it a single board.
2) Integrate the USB watchdog with an AtMega328 and use a software watchdog for more flexibility.
- I have done this with your Grove MiniPro LP board using Grove connector J4 and software I have written. I can supply this code, but its part of a larger framework. I will be updating an open source repository on github with it shortly.
- Require complete high-low-high transistion on watch input, since in many cases a device can fail with the port stuck low or high.
- A couple of Grove connectors. A) Watchdog input. Connect to Dx Grove port on device. B) Other controls. Allow control of external RESET, relays, etc. - Add additional micro-usb that provides signals to the USB out to device using an on board FTDI, but not power. - Power comes from the switch. - This allows a RaspberryPi to use a USB serial port to send the watch signal and not have to wire any hardware ports.
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Post by SDL on Mar 5, 2018 14:18:51 GMT -8
John
Interesting idea.1) Integrate 555 timer based watchdog with USB power switch so its a plug+play with a single Grove cable. Yes, this could be done. And it would be useful. We have done something very similar in our SunControl board, but we have a bunch of other functionality on that board.1a) Make it a single board. Yes. Definitely.2) Integrate the USB watchdog with an AtMega328 and use a software watchdog for more flexibility. That would give you a lot more flexibility at the cost of a certain amount of reliability (your watchdog is dependent on the 328 working and staying working). Maybe we should add a hardware watchdog backup like we do on SunControl.- I have done this with your Grove MiniPro LP board using Grove connector J4 and software I have written. I can supply this code, but its part of a larger framework. I will be updating an open source repository on github with it shortly. I like it. Great use of that board.- Require complete high-low-high transistion on watch input, since in many cases a device can fail with the port stuck low or high. You bet it can.- A couple of Grove connectors. A) Watchdog input. Connect to Dx Grove port on device. B) Other controls. Allow control of external RESET, relays, etc. - Add additional micro-usb that provides signals to the USB out to device using an on board FTDI, but not power. - Power comes from the switch. - This allows a RaspberryPi to use a USB serial port to send the watch signal and not have to wire any hardware ports. Hit me again with this one? Maybe a diagram? BPRead more: forum.switchdoc.com/thread/467/improvements-watchdog-usb-power-switcher#ixzz58uoCAXpu
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