# HC-05 Bluetooth shutting down **URL:** \ **Category:** Support\ **Created:** [7 February 2021 22:18 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367 "2021-02-07T22:18:57Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Allan101600](https://avatars.discourse-cdn.com/v4/letter/a/6bbea6/32.png) [@Allan101600](https://forum.core-electronics.com.au/u/Allan101600)\ **Post date:** [7 February 2021 22:18 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/1 "2021-02-07T22:18:57Z")
Hi, I am having a problem with a HC-05 Bluetooth module. I have a HM-10 and have used it with no problem. I have checked many forums with no luck. I can get it to connect and pair with difficulty, to different apps and devices, however the max time is about 10 seconds. It drops connection and soon after **shuts down (no led )** or just shuts down. I think the unit is faulty (onboard voltage regulator under load) I have been able to enter AT command mode, with no problems (not shutting down) I measured the following, scamming current- alternating between 6 and 45 milli-amps, paired 20 milli-amps, when it shuts off ( no led) 8 to 14 milli-amps. Your advice would be appreciated. Thank you. Allan Mathers ---
**Author:** ![Bryce](https://yyz2.discourse-cdn.com/flex028/user_avatar/forum.core-electronics.com.au/bryce/32/3631_2.png) [@Bryce](https://forum.core-electronics.com.au/u/Bryce)\ **Post date:** [7 February 2021 23:27 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/2 "2021-02-07T23:27:46Z")
Hi Allan, Welcome to the forum! How unusual, what board are you using the HC-05 with and what script are you running on the microcontroller? It sounds like there may be an issue with the onboard regulator. Although usually those issues either cause a complete failure of the board or are more inconsistent in the amount of time before failure, but we’ll need to take a closer look at what’s going on with the script first to be able to determine what’s going on with it. Thanks. ---
**Author:** ![Allan101600](https://avatars.discourse-cdn.com/v4/letter/a/6bbea6/32.png) [@Allan101600](https://forum.core-electronics.com.au/u/Allan101600)\ **Post date:** [9 February 2021 06:29 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/3 "2021-02-09T06:29:24Z")
Did you receive my reply? My email said it failed. . ---
**Author:** ![Allan101600](https://avatars.discourse-cdn.com/v4/letter/a/6bbea6/32.png) [@Allan101600](https://forum.core-electronics.com.au/u/Allan101600)\ **Post date:** [10 February 2021 01:43 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/4 "2021-02-10T01:43:41Z")
I am using a ZS-040 board. The script is from the ARDUINO project hub “ Getting Started with HC-05 Bluetooth Module & Arduino” and I am using the recommended app, Bluetooth Terminal on galaxy a30 phone. I am able to get it to connect and send a command, which appears not to work, then it disconnects and quite often shuts down. ```auto /* HC05 - Bluetooth AT-Command mode modified on 10 Feb 2019 by Saeed Hosseini https://electropeak.com/learn/ */ #include SoftwareSerial MyBlue(2, 3); // RX | TX int flag = 0; int LED = 8; void setup() { Serial.begin(9600); MyBlue.begin(9600); pinMode(LED, OUTPUT); Serial.println("Ready to connect\nDefualt password is 1234 or 000"); } void loop() { if (MyBlue.available()) flag = MyBlue.read(); if (flag == 1) { digitalWrite(LED, HIGH); Serial.println("LED On"); } else if (flag == 0) { digitalWrite(LED, LOW); Serial.println("LED Off"); } } ``` Thank you for your assistance ---
**Author:** ![Bryce](https://yyz2.discourse-cdn.com/flex028/user_avatar/forum.core-electronics.com.au/bryce/32/3631_2.png) [@Bryce](https://forum.core-electronics.com.au/u/Bryce)\ **Post date:** [10 February 2021 04:08 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/5 "2021-02-10T04:08:16Z")
Hey Allan, That’s quite interesting, I’m not seeing any obvious indicators that would cause an error such as that, also it seems clear that it’s almost certainly not a problem with the connection to the board itself, as otherwise you likely wouldn’t be able to interact with it correctly via AT commands. I’d recommend replying to your order confirmation email and link this post ([HC-05 Bluetooth shutting down - #3 by Allan101600](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/3)) we may have a faulty bluetooth breakout in this case. Please let me know if there’s anything else that I can help you with 😁 ---
**Author:** ![Allan101600](https://avatars.discourse-cdn.com/v4/letter/a/6bbea6/32.png) [@Allan101600](https://forum.core-electronics.com.au/u/Allan101600)\ **Post date:** [10 February 2021 04:57 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/6 "2021-02-10T04:57:07Z")
Thank you for your reply. I am a customer of yours, but did not buy this item from you. In future I will check your store before purchasing. ---
**Author:** ![Bryce](https://yyz2.discourse-cdn.com/flex028/user_avatar/forum.core-electronics.com.au/bryce/32/3631_2.png) [@Bryce](https://forum.core-electronics.com.au/u/Bryce)\ **Post date:** [10 February 2021 05:00 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/7 "2021-02-10T05:00:03Z")
Hey Allan, That’s okay, we can still help out! Just can’t have it sent back is all. Have you tried running the module with any other scripts or microcontrollers so far? ---
**Author:** ![Allan101600](https://avatars.discourse-cdn.com/v4/letter/a/6bbea6/32.png) [@Allan101600](https://forum.core-electronics.com.au/u/Allan101600)\ **Post date:** [10 February 2021 06:12 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/8 "2021-02-10T06:12:48Z")
Yes I have tried other scripts and also tried an old Samsung Ace with different apps. Best I could do was connect, sent one or two commands with no response, followed by disconnection and then possible shutdown. ---
**Author:** ![Allan101600](https://avatars.discourse-cdn.com/v4/letter/a/6bbea6/32.png) [@Allan101600](https://forum.core-electronics.com.au/u/Allan101600)\ **Post date:** [10 February 2021 06:25 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/9 "2021-02-10T06:25:26Z")
Just tried another UNO, same result ---
**Author:** ![Bryce](https://yyz2.discourse-cdn.com/flex028/user_avatar/forum.core-electronics.com.au/bryce/32/3631_2.png) [@Bryce](https://forum.core-electronics.com.au/u/Bryce)\ **Post date:** [12 February 2021 01:25 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/10 "2021-02-12T01:25:58Z")
Sounds like you may have a bad HC-05, I’d get in touch with your supplier and see what they can do on their warranty process for you, I’m not sure what could be causing the issues here. ---
**Author:** ![Oliver](https://yyz2.discourse-cdn.com/flex028/user_avatar/forum.core-electronics.com.au/oliver/32/3315_2.png) [@Oliver](https://forum.core-electronics.com.au/u/Oliver)\ **Post date:** [12 February 2021 05:03 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/11 "2021-02-12T05:03:29Z")
Hi Allan, Interesting. I’d recommend using this app: > > > 'Serial Bluetooth Terminal' is a line-oriented terminal / console app for microcontrollers, arduinos and other devices with a serial / UART interface connected with a bluetooth to serial converter to your android device. > > This app supports different bluetooth versions: > \- Bluetooth Classic > \- Bluetooth LE / Bluetooth Low Energy / BLE / Bluetooth Smart > > This app supports different bluetooth devices: > Bluetooth Classic (implementing standard Bluetooth SPP profile): > \- HC-05, HC-06, ... > \- Raspberry Pi... It’s my go-to for debugging and working with Bluetooth devices. ---
**Author:** ![Allan101600](https://avatars.discourse-cdn.com/v4/letter/a/6bbea6/32.png) [@Allan101600](https://forum.core-electronics.com.au/u/Allan101600)\ **Post date:** [12 February 2021 05:40 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/12 "2021-02-12T05:40:54Z")
Have already contacted the supplier and received a refund through eBay. I will order a HC-05 through your firm. I want to verify that the HC-05 was faulty. Being that it is an uncommon fault. ---
**Author:** ![Allan101600](https://avatars.discourse-cdn.com/v4/letter/a/6bbea6/32.png) [@Allan101600](https://forum.core-electronics.com.au/u/Allan101600)\ **Post date:** [12 February 2021 05:43 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/13 "2021-02-12T05:43:50Z")
I am ordering another HC-05 through Core, once it arrives I will download and try out the app you recommend. Thank you. ---
**Author:** ![Owen](https://yyz2.discourse-cdn.com/flex028/user_avatar/forum.core-electronics.com.au/owen/32/2948_2.png) [@Owen](https://forum.core-electronics.com.au/u/Owen)\ **Post date:** [12 February 2021 05:44 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/14 "2021-02-12T05:44:38Z")
Hey Allan, No worries, hopefully that solves the issue but keep us posted with the results! ---
**Author:** ![Allan101600](https://avatars.discourse-cdn.com/v4/letter/a/6bbea6/32.png) [@Allan101600](https://forum.core-electronics.com.au/u/Allan101600)\ **Post date:** [25 February 2021 10:19 UTC](https://forum.core-electronics.com.au/t/hc-05-bluetooth-shutting-down/9367/15 "2021-02-25T10:19:26Z")
Hi Everyone, I got a HC-05 through Core and everything is fine, thank you for your responses. My old HC-05 was responding very erratically and I couldn’t find anyone on the web with the same problem. I don’t like to blame a component until I have exhausted all possibilities.It’s good to have such a forum to advise and get feedback.