How to connect non grove sensor to grovepi?

Archives GrovePi
1

hi,
i would like to connect a magnetic door sensor (which is non grove sensor) to grove pi , may i know how can connect it?? i not sure how use the 4 pin converter since the magnetic door sensor is only have 2 pin which is one connect to the GND and another to PWM0
LARGE this the sensor

2

I noticed that no one has responded; does this imply that one cannot connect non-grove sensors with the GrovePi? or are there any specific instructions on the dos and don’ts of connecting non-Grove supported sensors?

Would appreciate some feedback.

Thanks

3

Hi @tpjf09-rpi,

Technically it should work, but unfortunately, the firmware doesn’t support this functionality. For this thing to happen, interrupts have to be used on the GrovePi and we’re not sure if there’s any room left for features on it.

With that being said, let us investigate this and figure out if we can cram this on our firmware. We’ll be back with some figures.

Thank you!

4

That would be very desirable for sure and I hope that it’s doable. Could you provide a timeline too?

Thanks

5

@RobertLucian Robert; I would like to know how to use some of the Seeed.io sensors that do not have rpi support eg> the Gas sensor
http://wiki.seeedstudio.com/Grove-Gas_Sensor-MQ9/

It does not have a rpi/python support; are there any instructions on how to use this via GrovePi?

Thanks

6

Hi @tpjf09-rpi,

First of all, this may take us some time ( > 1 week) because we first need to develop it and then when it’s all good we have to test it. I might give you in the mean time a “preview” firmware that you can use, but first we need to get there.

Second of all, we’re not sure if all grove sensors work on the GrovePi, but I can assure you a large part of it works. Even if there isn’t any documentation on how to use it on the GrovePi, you can still look at the sensor’s description and see if it’s an analog or digital sensor. If that’s the case, then it will work in all cases on the GrovePi.
If it implies some sort of signal detection or doing something with a signal, then it’s probable that it doesn’t work.
As for sensors/actuators on I2C that’s even better, because the I2C port is shared with that of the Raspberry Pi, which means you can just straight out use/develop a library for the Pi and thus, bypass the GrovePi completely.

If there are any other questions, please let me know. And when I’ll have something to address your magnetic sensor, I’ll let you know.

Thank you!

7

Thanks @RobertLucian - really appreciate the quick responses. I’m pretty conservative when I jump into new technologies as I have been burned a couple of times; I like the GrovePi for the features offered but I also want to be able to have a fairly open system.

Take for example low cost RF based devices:

  • Etekcity Remote Control Outlet Wireless Light Switch
  • Bunker Hill Wireless Security Driveway Alert System
  • Temp/Humidity sensors

Based on your comment re signal detection; is it safe to say RF are not supported? If so can you recommend other low cost sensor options?

I’m trying to layout my deployment plan before going too far down a path of no return!

Thank again - I’m always learning!!!

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Hi @tpjf09-rpi,

Based on your comment re signal detection; is it safe to say RF are not supported? If so can you recommend other low cost sensor options?

No, I was referring to what the GrovePi has to do and I wasn’t talking about what data a sensor can capture (or do in the case of an actuator). If the interface is supported on the GrovePi, then go for it.

The “big” interface you have at hand with the GrovePi is GPIO for the GrovePi, which branches into the following 4 operations: digital outputting to a pin, digital inputting to a pin, analog writing to a pin and analog reading.
The analog output function doesn’t explicitly output a continuous voltage, but rather it mimics that with the use of PPM signals. This is rather useful if you want to control servos or servo controllers, but for that you already have the PivotPi.

There are also other interfaces supported, but only for the couple sensors we support (the dust sensor, the IR receiver, the grove LED bar, chainable LEDs and so on). In order to see which sensors we support, you might want to look over the source code of grovepi.py.

Don’t forget that there’s also the serial port on the GrovePi that’s basically a bypass to the one on the Pi. You can use that for a multitude of devices that use the Grove port and are serial. For instance, the following kit works on serial and we have an example program for it:
http://wiki.seeedstudio.com/Grove-433MHz_Simple_RF_Link_Kit/

For temperature and humidity it depends on your needs: there’s the classic DHT11 that we support on our current firmware:

As for other functionalities on the GrovePi, we’re pondering the idea of implementing a sort of interrupt service that’s configurable on the Pi within Python.

Please let me know if you have further questions regarding the end devices (sensors/actuators). By the way, just so you know, during this time we’re working on improving/fixing the GrovePi. So, you can come up with suggestions on what you want to see in it while we are at it.

Thank you!

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@RobertLucian Hi; I’m back with my experiment: I tried to use the GrovePi Simple RL Link Kit to Tx/Rx signals for an outlet https://amzn.to/2uUsvET . I used the python receiver example to hopefully get a read on the signals from the ZAP control but I’m getting nothing… see attached2018-07-21_093247

Is there hope in getting this functionality to primarily send ON/OFF commands to the outlet or similar devices?

I tried both serial ports on the GrovePi board.

Would appreciate some help.
Thanks

10

Hi @RobertLucian; What am I doing wrong? I really would like to get this working. Are there any checks or tools needed to test the functionality of the kit?

Thanks

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Hi @tpjf09-rpi,

When working on that I remember the devices were supposed to be very close (meters close). Can you check that by putting both devices near each other?

Thank you!