#trouble uploading firmware to my Happymodel EP1 receiver

53 messages · Page 1 of 1 (latest)

bitter hazel
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Hi. I'm having trouble uploading firmware to my Happymodel EP1 receiver. I was able to upload the firmware to it before, but recently it automatically switched to bootloader mode (the green light stays on all the time). I tried shorting the PAT boot, connecting it to other FCs, checking the connections, trying other UARTs, trying with and without telemetry. The settings in BF are definitely correct. I have two other receivers, EP1 and EP2, and everything works on them. I did everything through Betaflight Passthrough because I'm unable to do it via Wi-Fi (it switches to bootloader mode). I'm thinking about purchasing a USB to UART converter because I don't know what else to do. If anyone has any ideas, I would be very grateful for the help.

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bold snow
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dji? analog?

bitter hazel
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I have drones with both analog and digital systems. I tried on both as well as with the VTXs disconnected.

bold snow
bitter hazel
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Unfortunately, this method doesn't work either. So, I will buy a UART adapter.

bitter hazel
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Hi. I tried using the UART converter, but it's still not working. Everything is connected properly, I have the boot pad shorted, the USB converter is recognized by the computer, and everything is exactly as described in the instructions you sent me, but it still doesn't work. Do you have any other suggestions?

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bitter hazel
bold snow
# bitter hazel

could you try without the intermediate dupont connector part please, soldering the receiver wiring directly into the back of the adapter.

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also try wiring RX to RXD and TX to TXD in case the adapter is incorrectly labeled, unless you've already used this adapter sucessfully before and proven the labels are correct

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also set the jumper so that VCC is 5v

bitter hazel
bitter hazel
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The same problem persists. I switched the VCC to 5V, soldered everything directly, and tried connecting RXD to RX and TXD to TX, as well as the opposite. Unfortunately, it still doesn't work. Is it possible that the receiver itself is damaged?

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bitter hazel
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# bitter hazel Yes

could you please post the latest !log file from your most recent attempt please

unkempt otterBOT
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See the following image to save a log file from the configurator

bitter hazel
bold snow
# bitter hazel Here you go.

have you used the adapter before and successfully flashed or at least connected to the device (a different one)?

bitter hazel
bitter hazel
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It didn’t work with the EP2 either; I’m getting the same error through UART. Last time, I tried with exactly this receiver using Betaflight passthrough, and everything worked. Should it still work if the receiver isn’t in bootloader mode, or do I need to put it into bootloader mode?

bold snow
bitter hazel
bold snow
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then, it could be that your other receiver is borked.
maybe contact the supplier or happymodel themselves and ask for replacement..

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because it shouldn't be that hard to get it flashed via uart, as you have already proven

bitter hazel
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I understand. Thanks a lot for your help!

blissful sedge
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i have one BetaFPV RX that i typically need to use the LUA script to put it in WiFi mode, after that i can flash via Betaflight passthrough. it's stupid, but maybe this will work for you too.

bitter hazel
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Hi,
I bought a new EP1 receiver from a different seller after returning the previous one and receiving a refund. I’ve been using this new one for about three months without any issues—until today. After just four flights, it randomly bricked itself again. At first, it would connect, but the RSSI was extremely low. Then it seemed like it was trying to connect, but my radio didn’t show any active link. Eventually, it stopped connecting entirely and now appears to be completely bricked. I’ve tried reflashing it via UART, Wi-Fi, and Betaflight Passthrough, but nothing works since the receiver no longer responds or enters Wi-Fi mode. I honestly don’t know what to do at this point, since the exact same issue has happened again. I have no idea what’s causing it.

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bitter hazel
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Normally, the bootpad is not shorted, but I tried to fix it via UART and now it is.

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bitter hazel
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It is exactly the same as in the case described above.

bitter hazel
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I managed to recover the bricked EP1 receiver. I tried a few more things, and what finally worked was flashing via UART — but with a specific method: after starting the flashing process, I waited about 3 seconds before connecting the +5V power. That’s when the receiver was recognized and the new firmware was successfully flashed.

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Also, I have a feeling that the UART on the drone where the EP1 was installed might be faulty or unstable. I'm going to try connecting the receiver to a different UART and see if that makes a difference.

bitter hazel
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I'm having another issue with my EP1 receiver.

I recently bought a new one, installed it in my drone, and updated everything to version 3.5.4.

Today was my first flight with this receiver, and I immediately noticed that the Tx Power wasn’t showing up on the OSD or in telemetry, even though my Betaflight configuration is exactly the same as before. I tried four different firmware versions, but telemetry still didn’t show any Tx Power value.

Then I realized the signal range was extremely poor. I was getting failsafes in areas where I used to fly with no problems on 25mW — and now I was using 500mW, which is very strange.

I’m not sure whether it’s a misconfiguration issue or something related to the new firmware. I still need to test with another receiver to compare.

Also, in another drone where I didn’t change anything except upgrading the firmware from 2.x.x to 3.5.4, I’ve noticed a similar issue: Tx Power always shows as zero, no matter what I change. I haven’t flown that drone yet, so I can’t say for sure about the range, but it may be affected too.

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One thing I did change in the first drone — as I mentioned earlier — was switching to a different UART. However, I don't believe this is causing the issues

bold snow
unkempt otterBOT
bold snow
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TPWR should show up in the radio Telemetry as it's part of the 10 basic link stats..

Telemetry being off in betaflight is a factor why it won't show up in the OSD.

bitter hazel
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Hi, out of the 18 telemetry sensors, all the main 16 are showing up correctly. Telemetry is enabled in Betaflight, and RSSI_ADC (Analog RSSI input) is disabled.

I’ve gone through all of the Betaflight settings and everything looks fine. The only sensor not reporting is TxPower, which is stuck at 0mW. There's also AM, but I'm not even sure what that one is for.

I’ve already checked all the basic things like the TX/RX wiring and other connections, and everything seems to be in order.

When I get home, I’ll test it on different UARTs and receivers, and I’ll also run a benchtest.

Also, I wanted to ask — has anyone reported any known issues with version 3.5.4 on EP1 receivers?

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bitter hazel
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So there is a problem with telemetry

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bitter hazel
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I know, it is in the radio

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bitter hazel
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Bf?

bold snow
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i.e. what BETAFLIGHT version

bitter hazel
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I don't remember the version right now. I'll check it when I get home and let you know.

bitter hazel
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in one drone i have 4.4.3 and in secound 4.4.2 i will try to ubgrade.

bitter hazel
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I flashed the latest version of Betaflight, but I’m still getting the same issue. I'm attaching some photos of the telemetry below.

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