# Pi 4 Power warning **URL:** \ **Category:** Notecarrier Pi\ **Created:** [December 12, 2020, 12:23pm UTC](https://discuss.blues.com/t/pi-4-power-warning/70 "2020-12-12T12:23:11Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![acsarnaik](https://avatars.discourse-cdn.com/v4/letter/a/f17d59/32.png) [@acsarnaik](https://discuss.blues.com/u/acsarnaik)\ **Post date:** [December 12, 2020, 12:23pm UTC](https://discuss.blues.com/t/pi-4-power-warning/70/1 "2020-12-12T12:23:11Z")
I am using a Pi hat with wide band Notecard on a Pi 4 with a 3Amp power supply. I am still getting warning message about the power supply. What is the minimum power that is required please. ---
**Author:** ![zfields](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/zfields/32/29_2.png) [@zfields](https://discuss.blues.com/u/zfields)\ **Post date:** [December 13, 2020, 1:27am UTC](https://discuss.blues.com/t/pi-4-power-warning/70/2 "2020-12-13T01:27:52Z")
Hi @acsarnaik, We expect a maximum surge of ~2A, so your findings are a bit surprising. Can you speak to how your Raspberry Pi is configured? Do you have other peripherals, or do you only have a Pi Hat hooked up? Also, are you using standoffs on the Pi Hat to prevent it from shorting on the HDMI output? We don’t list the max current in our DC Characteristics on the [datasheet](https://dev.blues.io/hardware/notecard-datasheet/note-wbex-500/#dc-characteristics). However, under [**Power Information**](https://dev.blues.io/hardware/notecard-datasheet/note-wbex-500/#power-information), it states: > “Furthermore, when in a region requiring the use of GSM, it can spike to up to nearly 2A for a few milliseconds.” ---
**Author:** ![acsarnaik](https://avatars.discourse-cdn.com/v4/letter/a/f17d59/32.png) [@acsarnaik](https://discuss.blues.com/u/acsarnaik)\ **Post date:** [December 13, 2020, 1:52am UTC](https://discuss.blues.com/t/pi-4-power-warning/70/3 "2020-12-13T01:52:02Z")
Hello @zfields, I do not have other peripherals, only the Pi hat. I do not have standoff. Remember this is a Pi4, so the HDMI port is has a fairly good amount of gap. The power supply has 3A capability. This is the wideband Notecard, and has the external antenna. Hope this helps. ---
**Author:** ![zfields](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/zfields/32/29_2.png) [@zfields](https://discuss.blues.com/u/zfields)\ **Post date:** [December 13, 2020, 1:59am UTC](https://discuss.blues.com/t/pi-4-power-warning/70/4 "2020-12-13T01:59:05Z")
That’s all good information! I want to discuss your setup with one of our hardware folks. I will report back once I have more specifics to share. In the meantime, if you think of anything else that may provide us with a more clear picture, please reply to this thread with those details. Thanks! ---
**Author:** ![Francois](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/francois/32/15_2.png) [@Francois](https://discuss.blues.com/u/Francois)\ **Post date:** [December 13, 2020, 1:42pm UTC](https://discuss.blues.com/t/pi-4-power-warning/70/5 "2020-12-13T13:42:37Z")
We’ve been using the Pi4 for several months now in a similar configuration. Some suggestions: - Are you using a genuine Raspberry power supply? I know the cost a few more $ but we’ve had issue with other brands. If you are using another brand with a USB cable, we’ve also had issues with, ah, “eBay” cables. In both cases we measured the output at the USB-C end and we could see the voltage dropping. - The issue might be on the draw on the HDMI side with 7" or even smaller screen, even with their own separate USB power . Do you see the same issue when you SSH/VNC into your Pi without HDMI? What I can confirm is both the narrow and wideband unfortunately draw too much for a Pi Zero – even rebooting the Zero. ---
**Author:** ![acsarnaik](https://avatars.discourse-cdn.com/v4/letter/a/f17d59/32.png) [@acsarnaik](https://discuss.blues.com/u/acsarnaik)\ **Post date:** [December 17, 2020, 12:54am UTC](https://discuss.blues.com/t/pi-4-power-warning/70/6 "2020-12-17T00:54:42Z")
I am using a good power supply with an attached cable and not a generic one. I have connected the Pi to a LED monitor. I see the same issue when I VNC into the Pi. ---
**Author:** ![Francois](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/francois/32/15_2.png) [@Francois](https://discuss.blues.com/u/Francois)\ **Post date:** [December 17, 2020, 3:07am UTC](https://discuss.blues.com/t/pi-4-power-warning/70/7 "2020-12-17T03:07:07Z")
Test 1 - I replaced the 2.5A supply by a 3A Pi4 power supply for my Pi3B+ (less hungry for power). - no HDMI, speaker connected, just the ethernet cable - Using a Notecard Wideband on a Carrier hat with firmware 12200 On one SSH I run the following code: _while true; do vcgencmd get\_throttled 1; sleep 1; done_ On another SSH execute a Notecard command, like a hub.set. The code hangs (Python3) –\> 0x50005 indicating under voltage Ctrl-C to break the code –\> 0x0 (normal voltage) Test 2 I put the card in periodic mode. That stops code to the Notecard from hanging when the voltage is low. When the LED light is off (indicating no RX/TX) –\> 0x0 As soon as the LED light goes on –\> 0x50005 NOTE: I am not talking about 2,3 or 4 0x5005, more like a continuous series of 0x5005 I have a USB meter between the power supply and the USB cable to the Pi3B+. I do not see the voltage drop below 5.2v or a substantial change in the amperage. So either my meter doesn’t react fast enough or the issue occurs after the power input to the Notecard. @ [acsarnaik](https://discuss.blues.com/u/acsarnaik) are you using a narrow band or wideband Notecard? ---
**Author:** ![acsarnaik](https://avatars.discourse-cdn.com/v4/letter/a/f17d59/32.png) [@acsarnaik](https://discuss.blues.com/u/acsarnaik)\ **Post date:** [December 17, 2020, 4:10am UTC](https://discuss.blues.com/t/pi-4-power-warning/70/8 "2020-12-17T04:10:03Z")
Hello @Francois, I am using the wideband notecard on the Pi hat. I will try to run the command in a loop to see how it behaves overnight. ---
**Author:** ![Francois](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/francois/32/15_2.png) [@Francois](https://discuss.blues.com/u/Francois)\ **Post date:** [December 17, 2020, 11:12am UTC](https://discuss.blues.com/t/pi-4-power-warning/70/9 "2020-12-17T11:12:00Z")
Another Pi3B+ is not showing any 0x5005. I ruled out a few differences: - ethernet vs. WiFi - 2.5A vs 3A supply That leaves - narrowband vs wideband - Hat vs. USB My head is hurting… I have a Pi4 with hat+wideband+3A+continuous mode that has no problem. Even when additional code runs on a bonnet. ---
**Author:** ![Francois](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/francois/32/15_2.png) [@Francois](https://discuss.blues.com/u/Francois)\ **Post date:** [December 17, 2020, 1:47pm UTC](https://discuss.blues.com/t/pi-4-power-warning/70/10 "2020-12-17T13:47:01Z")
Same Pi3B+: - removed the hat with the wideband Notecard - inserted a narrowband with usb –\> same problem So this rules out the usb vs. hat and the wideband vs narrowband The 0x5005 occurs exactly at this line of the code: port = busio.UART(board.TX, board.RX, baudrate=9600) switching to I2C makes no difference: port = busio.I2C(board.SCL, board.SDA) ---
**Author:** ![gwolff](https://avatars.discourse-cdn.com/v4/letter/g/a88e57/32.png) [@gwolff](https://discuss.blues.com/u/gwolff)\ **Post date:** [December 17, 2020, 6:39pm UTC](https://discuss.blues.com/t/pi-4-power-warning/70/11 "2020-12-17T18:39:41Z")
**FYI: Thus far I have been unable to reproduce this issue at all** It’s not clear to me yet what the controlling variable is. (Notecard, carrier, Raspberry Pi, etc.) Here’s my report of what I’ve tried. ## Hardware Info ### Command: `cat /proc/cpuinfo` ### Response (clipped) ```bash Hardware : BCM2835 Revision : a020d3 Serial : 00000000c964f548 Model : Raspberry Pi 3 Model B Plus Rev 1.3 ``` ## OS Info ### Command: `cat /etc/os-release` ### Response (clipped) ```bash PRETTY_NAME="Raspbian GNU/Linux 10 (buster)" NAME="Raspbian GNU/Linux" VERSION_ID="10" VERSION="10 (buster)" VERSION_CODENAME=buster ID=raspbian ID_LIKE=debian ``` ## Power Flag Monitor Command ### Command: `while true; do vcgencmd get_throttled 1; sleep 1; done` Queries the power status flag every second. Recommend opening a separate SSH terminal to run this command on the Raspberry Pi ### Expected Response (clipped): ```auto throttled=0x0 throttled=0x0 throttled=0x0 throttled=0x0 throttled=0x0 throttled=0x0 throttled=0x0 throttled=0x0 throttled=0x0 ``` ## Setup Config **Power supply:** Samsung 2A phone power supply **Cable:** 2 meter USB-A to micro USB **Notecard:** ### `card.version` ```json {"body": { "org":"Blues Wireless", "product":"Notecard", "version":"notecard-1.5.2", "ver_major":1, "ver_minor":5, "ver_patch":2, "ver_build":12200, "built":"Dec 7 2020 19:28:29" }, "version":"notecard-1.5.2.12200", "device":"dev:864622040036788", "name":"Blues Wireless Notecard", "type":11, "sku":"NOTE-NBNA500" } ``` ### `card.wireless` ```json { "status":"{network-up}", "count":1, "net":{ "iccid":"89011703278520616353", "imsi":"310170852061635", "imei":"864622040036788", "modem":"BG95M1LAR02A04_BETA0611A_01.001.01.001_BETA0611A", "band":"LTE BAND 12", "rat":"emtc", "rssir":-73, "rssi":-74, "rsrp":-102, "sinr":105, "rsrq":-13, "bars":1, "mcc":310, "mnc":410, "lac":xxxx, "cid":xxxxxxxx, "updated":1608222786 } } ``` ### Notecarriers - Notecarrier-AL - Notecarrier-B - Notecarrier-Pi ### Notecard Comms Interfaces - Uart over USB via Node Red with Notecarrier-AL and Notecarrier-B - I2C with Notecarrier Pi using Python3 and note-python library ### Hub (Cell Network) Connection Policy **Continuous** Which means the modem is on continuously. ---
**Author:** ![Francois](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/francois/32/15_2.png) [@Francois](https://discuss.blues.com/u/Francois)\ **Post date:** [December 17, 2020, 11:37pm UTC](https://discuss.blues.com/t/pi-4-power-warning/70/12 "2020-12-17T23:37:02Z")
@acsarnaik you may hold the key to getting to the bottom of this: Greg cannot reproduce (as you can see above). When I switched my microSD, carrier+notecard+power supply to a new Pi4 – problem solved – it has been running for hours and I can’t get it to report an error. In my case, I could just forget about Pi3B+ and just use Pi4, but it would be nice to be able to understand why you have an issue on a Pi4. Can you please run the steps Greg is mentioning above? ---
**Author:** ![Francois](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/francois/32/15_2.png) [@Francois](https://discuss.blues.com/u/Francois)\ **Post date:** [December 18, 2020, 2:11am UTC](https://discuss.blues.com/t/pi-4-power-warning/70/13 "2020-12-18T02:11:31Z")
[Python3 quick utility](https://github.com/TaDahCorp/pi_voltage_monitor) (version 1.0) to track low voltage: ---
**Author:** ![gwolff](https://avatars.discourse-cdn.com/v4/letter/g/a88e57/32.png) [@gwolff](https://discuss.blues.com/u/gwolff)\ **Post date:** [December 18, 2020, 9:10pm UTC](https://discuss.blues.com/t/pi-4-power-warning/70/14 "2020-12-18T21:10:47Z")
It looks like using python 3.x instead of python 2.7 has resolved the issue. ---
**Author:** ![Francois](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/francois/32/15_2.png) [@Francois](https://discuss.blues.com/u/Francois)\ **Post date:** [December 19, 2020, 1:44am UTC](https://discuss.blues.com/t/pi-4-power-warning/70/15 "2020-12-19T01:44:58Z")
Good news. Puzzling that 2.7 vs. 3.0 would have an impact all the way down to power warnings.