Converting the Duet WiFi to use an external antenna
The recent release of the ESP-07S WiFi module has provided an easier route to adding an external antenna to the Duet WiFi, by replacing the ESP-12F module on the Duet by the ESP-07S. The 'S' is important, because the older ESP-07 device had insufficient flash memory.
Please note, modifying your Duet Wifi in this way will void the warranty. The tricky bit is removing the ESP-12F, which requires hot air desoldering equipment (remember to remove the SD card from its socket first). Or you could use Chip Quik or similar low melting point solder to desolder it. After that you just need to clean up the pads using solder wick, apply some no-clean flux to them and to the ESP-07S, and solder the new device in place using a fine-tipped soldering iron, with the antenna connector end near the board edge. The ESP-07S doesn't have pads along the back as the ESP-12F did, but that doesn't matter because they were not used on the Duet.
Use M997 S1 to do the initial firmware upload to the new WiFi module. I used the 1.20alpha build of DuetWiFiServer along with DuetWiFiFirmware 1.20beta1. No firmware or configuration changes were needed.
Martin_S last edited by
I want one… badly
I'm having ajax disconnects again.
Will you make a step by step guide of this? That would be sweet.
Some of us are a bit underskilled around electronics.
Before concluding that an external antenna will solve the problem, check the RSSI and the other items at https://duet3d.com/wiki/WiFi_disconnections_and_AJAX_timeout_errors.
Edward_Spud last edited by
For anyone interested in replacing the WiFi module, link to ESP-07S data sheet below:
Depending upon your location and your preferred supplier, the module will cost between £3.00 and <£2.00, e.g. http://www.electrodragon.com/product/esp-07s-esp8266-serial-wifi-module/
You will also need a IPEX/u.FL to SMA adaptor coax lead, similar to:
2.4GHz antenna, similar to:
I would guess that most hobbyists will have a spare 2.4GHz antenna somewhere in the house (i.e. supplied with that old WiFi router you previously upgraded) however if you do need to purchase, make sure you get one with a SMA to match the coax lead (or if you already have a RP-SMA antenna, make sure you purchase a Coax with a RP-SMA connector to suit! - you cannot mix RP-SMA and SMA connectors.
Willy510 last edited by
I did the modification on one of my Duet's and it did improve my signal strength but there are easier ways to do that than possibly ruining the control board. I would not recommend this mod for the novice or faint of heart. It can go really well or really bad in the space of a few seconds. But if you still want to do it one thing that wasn't mentioned is that you will have to load the wifiserver bin on to the new wifi module once you solder it on via USB and SD card using an M997 S1 command or at least thats how I got mine to work.
David, do you confirm that this module is OK?
Yes, the ESP-07S is OK.
Ok, I just changed my wifi module, but I can't set ssid/password (get "Bad or missing parameter"). Here are the logs:
>>> M997 S1 SENDING:M997 S1 Trying to connect at 460800 baud: success Erasing 302928 bytes... Uploading file... 5% complete 10% complete 15% complete 20% complete 25% complete 30% complete 35% complete 40% complete 45% complete 50% complete 55% complete 60% complete 65% complete 70% complete 75% complete 80% complete 85% complete 90% complete 95% complete Upload successful >>> M552 S0 SENDING:M552 S0 WiFi module started >>> M587 Sxxx Pxyyy SENDING:M587 Sxxx Pyyy M587: Bad or missing parameter >>> M122 SENDING:M122 === Diagnostics === Used output buffers: 1 of 32 (9 max) === Platform === RepRapFirmware for Duet WiFi version 1.20beta8 running on Duet WiFi 1.0 Board ID: 08DDM-9FAM2-LW4S8-6JTDG-3SD6Q-13YRX Static ram used: 15488 Dynamic ram used: 99136 Recycled dynamic ram: 64 Stack ram used: 4328 current, 5532 maximum Never used ram: 10852 Last reset 00:19:36 ago, cause: reset button or watchdog Last software reset reason: User, spinning module GCodes, available RAM 11504 bytes (slot 4) Software reset code 0x0003, HFSR 0x00000000, CFSR 0x00000000, ICSR 0x00400000, BFAR 0xe000ed38, SP 0xffffffff Error status: 0 [ERROR] Error status: 0 Free file entries: 10 SD card 0 detected, interface speed: 20.0MBytes/sec SD card longest block write time: 0.0ms MCU temperature: min 26.4, current 27.2, max 27.4 Supply voltage: min 1.7, current 1.7, max 1.7, under voltage events: 0, over voltage events: 0 Driver 0: ok Driver 1: ok Driver 2: ok Driver 3: ok Driver 4: ok Date/time: 1970-01-01 00:00:00 Cache data hit count 1442288766 Slowest main loop (seconds): 3.074205; fastest: 0.000033 === Move === MaxReps: 0, StepErrors: 0, FreeDm: 240, MinFreeDm 240, MaxWait: 0ms, Underruns: 0, 0 Scheduled moves: 0, completed moves: 0 Bed compensation in use: none Bed probe heights: 0.000 0.000 0.000 0.000 0.000 === Heat === Bed heater = 0, chamber heater = -1 === GCodes === Segments left: 0 Stack records: 1 allocated, 0 in use Movement lock held by null http is idle in state(s) 0 telnet is idle in state(s) 0 file is idle in state(s) 0 serial is ready with "M122" in state(s) 0 aux is idle in state(s) 0 daemon is idle in state(s) 0 queue is idle in state(s) 0 autopause is idle in state(s) 0 Code queue is empty. Network state is running WiFi module is idle Failed messages: pending 0, notready 0, noresp 0 WiFi firmware version 1.20b9 WiFi MAC address 5c:cf:7f:61:99:c5 WiFi Vcc 3.35, reset reason Turned on by main processor WiFi flash size 4194304, free heap 32376 HTTP sessions: 0 of 8 Socket states: 0 0 0 0 0 0 0 0 Responder states: HTTP(0) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0)
Are you putting the ssid and password inside double quote characters?
Yes. I tried with Pronterface (using single quote to prefix each lower case char), and with minicom. Same error each time.
Whatever I use as S/P values, I get the error.
Did I fry the esp module? I don't think, as the firmware was successfully updated, but…
I just upgraded to lastest stable firmwares (1.20), and all is now working fine!
I have a question… M122 returns:
WiFi signal strength -73dBm
But my router says:
Signal Noise RX Rate TX Rate -59 dBm -89 dBm 54.0 Mbit/s 65.0 Mbit/s
Why is there such difference in signal level? In fact, while I'm now using the ESP-07 with a +6dB gain antenna, the signal level returned by M122 didn't changes that much (I think I was around -75dB before)…
garyd9 last edited by
Large differences is wifi signal strength are normal for differing wifi devices. Each one "hears" the other differently. This can be due so many different factors it's impractical to enumerate. Usually, it's different radio power, different antennas, or different propagation paths.
In your case, it appears the router has "bigger ears" (better antenna.)
Ok, I see.
But why switching from the default ESP (no antenna) to the new one (6dB gain antenna) didn't change that much the signal strength returned by the Duet?
I don't have signal values given by the router with the default ESP (didn't think to read it at the time); so I don't know if it really changed. But the thing is I know have a much better connection: transfers are very fast and I don't get any disconnection anymore.
If M122 is telling you that the signal strength is -73dBm now, that is already very low. If it was even lower before, that would explain the disconnections you had.
Which wifi channel is your router set to? Does the reported signal strength vary if you switch between channels 1, 6 and 11?
Yes, it is low. But, as said, real transmissions work much better and faster, now. And no more disconnection.
I will make tests with different channels (I think I'm on channel 1 - the router is in auto and chose this one).
parovoZZ last edited by
I have WiFi signal strength -61dBm in three meters from the router. The ESP-07 has a very very weak antenna ((
I will change to ESP-07S or connect external to ESP-07.
Laptop, iPhone, Nokia etc. - everything works fine.
I used a wifi analyser on my phone, and noticed that there where 3 other AP on channel 1. In fact, it depends where I am in the house, and on the AP side, they are not detected. So the AP chose this channel. But on the printer side, they where as powerfull as my AP!
I moved to channel 3, unused by other wifi AP, and I now have -66dB strength…
ephemeris last edited by
Will this be available as a build option?