# Relay control widgets not working for relays in raspberry pi
**URL:** https://community.cumulocity.com/t/relay-control-widgets-not-working-for-relays-in-raspberry-pi/5878
**Category:** Forum
**Tags:** cumulocity, thin-edge-io
**Created:** [November 6, 2023, 10:23am UTC](https://community.cumulocity.com/t/relay-control-widgets-not-working-for-relays-in-raspberry-pi/5878 "2023-11-06T10:23:24Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@lall.gaurav](https://community.cumulocity.com/u/lall.gaurav)
#### Post date: [November 6, 2023, 10:23am UTC](https://community.cumulocity.com/t/relay-control-widgets-not-working-for-relays-in-raspberry-pi/5878/1 "2023-11-06T10:23:24Z")
Relay control widgets not working for relays in raspberry pi.
#### _ **Product/components** used and **version/fix** level:_
#### _Detailed explanation of the problem:_
I am using raspberry pi with sensors and relays. I am able to control the relays using shell command in cumulocity’s ‘Device Management’ platform. But when I am using ‘relay control’ widget in custom built application then I am getting a message ‘Operation not supported by this device’. Please help to solve this issue. I want to control relays using ‘RELAY CONTROL’ widget.
Thanks in advance.
#### _Error messages / **full error** message screenshot / **log** file:_
#### _Question related to a **free trial** , or to a **production (customer)** instance?_
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### Author:  [@Tristan\_Bastian](https://community.cumulocity.com/u/Tristan_Bastian)
#### Post date: [November 6, 2023, 10:33am UTC](https://community.cumulocity.com/t/relay-control-widgets-not-working-for-relays-in-raspberry-pi/5878/2 "2023-11-06T10:33:13Z")
Hi Lall,
your device needs to support the `c8y_Relay` operation: [Sensor library - Cumulocity IoT Guides](https://cumulocity.com/guides/reference/sensor-library/#c8y_relay)
In order for the Cumulocity UI to know that this operation is supported by your device, you will need to also list it within the `c8y_SupportedOperations`: [Device management library - Cumulocity IoT Guides](https://cumulocity.com/guides/reference/device-management-library/#announcing-capabilities)
Regards,
Tristan
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### Author:  [@lall.gaurav](https://community.cumulocity.com/u/lall.gaurav)
#### Post date: [November 8, 2023, 11:27am UTC](https://community.cumulocity.com/t/relay-control-widgets-not-working-for-relays-in-raspberry-pi/5878/3 "2023-11-08T11:27:58Z")
I am able to get the ‘Relay Control’ buttons. And also in the control tab of device I am getting ‘close relay’ and ‘open relay’ commands. But the actual relays of the device is not responding.
Please help.
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### Author:  [@Tristan\_Bastian](https://community.cumulocity.com/u/Tristan_Bastian)
#### Post date: [November 8, 2023, 12:06pm UTC](https://community.cumulocity.com/t/relay-control-widgets-not-working-for-relays-in-raspberry-pi/5878/4 "2023-11-08T12:06:24Z")
Your device/agent needs to support the `c8y_Relay` operation.
As you are using thin-edge, you need something on your device that receives the relay operation ([SmartREST - Cumulocity IoT Guides](https://cumulocity.com/guides/reference/smartrest-two/#relay-518)) processes it and updates it status. You would need to connect to the respective thin-edge mqtt topics on your local mqtt broker.
Regards,
Tristan
---
### Author:  [@lall.gaurav](https://community.cumulocity.com/u/lall.gaurav)
#### Post date: [November 13, 2023, 12:07pm UTC](https://community.cumulocity.com/t/relay-control-widgets-not-working-for-relays-in-raspberry-pi/5878/5 "2023-11-13T12:07:34Z")
I am able to send relay command to switch on the relay in raspberry pi. First I sent “relayState” : “OPEN” through postman to this path ‘/inventory/managedObjects’ then I have created a file named ‘c8y\_Relay’ in operations folder in raspberry pi. After that I used java program to receive relay command and send acknowledgement to cumulocity. I am able to see the relay operation ‘successful’ in control tab of 'device management. But when I am reloading the page the state of relay is not changing even after successful relay operation. Also When I am checking the state of c8y\_Relay in config it is not changing.
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### Author:  [@lall.gaurav](https://community.cumulocity.com/u/lall.gaurav)
#### Post date: [November 24, 2023, 11:18am UTC](https://community.cumulocity.com/t/relay-control-widgets-not-working-for-relays-in-raspberry-pi/5878/6 "2023-11-24T11:18:48Z")
I am sending acknowledgement in java as " client.publish(“c8y/s/us”, “503,c8y\_Relay,relayState:OPEN”.getBytes(), 2, false)". This is updating the status of relay in real time but status is not getting updated in cumulocity database. Please help in updating relay status in cumulocity database.
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### Author:  [@system](https://community.cumulocity.com/u/system)
#### Post date: [May 22, 2024, 11:19am UTC](https://community.cumulocity.com/t/relay-control-widgets-not-working-for-relays-in-raspberry-pi/5878/7 "2024-05-22T11:19:47Z")
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