As many have discovered doorbot has problems, I am really not sure what has happened or why…
To save a really long explanation, I changed the setup to use my board, rewired the RFID module to use an RJ-45 connector, and put a faceplate on the Ethernet cable that the Arduino connects to, and uses a short 1.5M cable.
Basically a bunch changed but the code, arduino and ethernet module remained the same. The issue we are experiencing now, is that the ethernet module either dies after a few minutes. In fact at home I have tried two different ethernet modules and can’t get them to work at all, even with demo code, and nothing else connected…
I am not sure if the ethernet modules are dead, or what is going on frankly… What is stranger is that if I use a genuine ethernet shield on a fake Arduino or genuine Arduino I am not having any issues. This leads me to think there is a hardware difference in the genuine, more modern ethernet shield and the old one, even though technically they both use a Wiznet 5100…
We are now in a situation where beyond buying genuine Arduino and ethernet modules I am not sure what we do… We’ve put a lot of time and a small amount of our own money into making this work and I am increasingly inclined to ditch Arduino because the ethernet capabilities are so limited and badly implemented.
The cost of a genuine Arduino and ethernet shield is right around Raspberry Pi prices which have all this build in…
I am hoping people can make some suggestions… I can get Doorbot working again for now using my own genuine ethernet shield, but I am reluctant to spend more time on this…
Sadly if this is the case the Raspberry Pi will need another shield design as it’s not compatible with Arduino shields.
Anyone got any thoughts? I am not looking for debugging but what the hell should we do?!
@MARKSE Do you know which place you bought these shields, the three I have all have solder bridges over multiple pins… This is likely an issue, not sure why it was working before and not now…
If there are solder bridges where there shouldn’t be I’d expect it to fail straight away or draw extra current and cause a quick failure. Sounds like you’ve got the second. The 5 Ethernet shields I got were all bought from eBay at your suggestion, from seller link-delight. As they were bought in Jan I doubt they’d be willing to talk about refunds. The downside of buying clones, bad or zero QC!
Can the bridges not be removed? I have desoldering equipment. What exactly is the RFID connectivity now? RFID module -> It’s connector -> RJ-45 socket -> 1.5M cable -> RJ-45 socket -> Arduino? By introducing the extra cable have you changed the voltages anywhere? Have you done a basic continuity check or measured resistances? When connected with a short cable the board may have been able to sink enough current to stay running. Now there’s extra resistance somewhere and at T+n with everything warming up it drops just below the level needed to stay operational. If you blast it with cold air from a hair dryer does it stay running longer?
I too have fallen foul of bad Chinese manufacturing. I got 10 USB WiFi plugs to use with RPi A+, 1 got so hot it melted the plastic, burnt my fingers and fell apart when I went to remove it. Another 2 got very warm and failed. A fourth failed while at a users office. 6/10 working is terrible. It’s got the users so worried that they regularly turn them off when leaving the house and I’d hoped to have them running 24x365.
Shame the RPi A+ doesn’t have built in RJ45 Ethernet, it’s a great little system. I’d go with RPi B+ or Beaglebone Black myself. You can SSH in to run diagnostics, have it log events locally as well as to a server. It can run various self diagnostics and send Pushover alerts out to people if there are issues. (Assuming you have a firewall allowing outbound only traffic). Let me know if you need a hand sourcing boards or desoldering.
And on the subject of access, I’d like to make Mondays my Makerspace day, come down and get working on some of my projects, away from the house and distractions. What should I do next?
The ethernet shield and rfid reader are both on the spi bus and clash unless one or the other is disabled
The initial code i gave you enabled the 2 spi devices as and when they were needed and disabled the other. So there were 2 spi enable lines. One for each device. Is this still working?
Or is it possible these 2 gpio’s have got crossed or switched on your shield?
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My instinct is to not have Arduinos doing IP. mbeds better – PHY built-in on many of the boards and more headroom in the µcontroller.
But if we’re building something integrated with web services, I really think Raspberry Pi and embrace Linux everywhere. Should be able to run the same software on remote webservers as locally.
But you’ve heard this before, I’m a broken record. And there’s no I-told-you-so, it’s always harder doing anything like this for reasons that you can never foresee and often creep up, subtly.
@MARKSE you are right they are unlikely to replace them… I am going to pop into the space and try and put a massive solder blob on and then use the desoldering iron on to remove the big blob.
@gordonendersby It works on a genuine ethernet shield, and the fake one doesn’t work even with the demo code.
@tobyspark I am not sure I agree, the Arduino is about as good as it need to be, the reason to use a Pi is for higher level functionality, and not having to handle to networking issues.