Yaesu FT-857D External Display

Please read all of this page before trying this project.
I won't be held responsible if you damage your equipment.

Latest page update. 03/August/2019

The actual project display, (now), has a 480 x 320 pixel touch screen. It's controlled by an Arduino MEGA microcontroller. 

A previous version used an Arduino Uno but the 'touch' feature wasn't available if the proper looking meter is displayed. A smaller 320 x 240 pixel screen is also an option for both variations, but has a limited display area for features. (See below) 

Connections to the 857 are by four wires. One to the 3.5mm Jack connector under the front panel, and 3 to the CAT port on the back panel.

The Arduino is powered by 5V via its USB connector.
I just use its programming cable plugged into my laptop USB.


Wiring from rig to MEGA. You can use any colour wire :-)


Blue-TX and Green-RX to port SERIAL3.

Orange from centre pin of 3.5mm jack to A12. The jack plugs under the front panel of the radio and carries the actual signal for the meter needle.
It's faster than reading the value via CAT.
Black is GND to either hole bottom row of double connector. 
The GND from the 3.5mm jack is not needed in my mind, it causes a hum on some HF bands.
Some extra software libraries need to be installed onto your computer before you program the Arduino.
These are included in the software .zip file.
CAT cable wiring.
The pins you see in the plug are the pins in the diagram.

'Nearly', every on screen item is touch controlable.
Frequency, step, mode, VFx, Lock, Dial speed, DSP, AGC and mode, MFx menu.


This is the 'Home' screen. The readout has a faster update cycle on this screen as the program doesn't read any other info from the rig.

Touch bottom right  --> for main menu.
Most of the main functions are accessed from this screen.

Use the bottom  <--  or  --> for next or previous menu/screen. 
Latest Update:

A/B - Toggles VFA/B
Touching VFx lower down now gives more options
including HoME and MEMory channels.

ND1/3 - Needle width.
MTR - Show/hide needle.
SCR - Redraw meter graphic.
SDT - Save needle settings to SD card.
M-/M+ Memory channel up/down.
RST - Resets the Arduino.
PSE - Pauses the display and turns the serial port off.
PRC - Proc function on 12m and above.

The screen shots in the following images were taken before the last project update.

When you touch the screen, a small round coloured dot shows left of screen to confirm the touch has been recognised by the system.
' 99% of the time :-) '

Touching the top left of the meter area 'RX' scrolls through the actual modes the meter needle shows when the rig is in RX mode.

> Touching the top right of the meter area 'TX' scrolls through the actual modes the meter needle shows when the rig is in TX mode.


Touching the area directly above the voltage readout brings up a blue panel with further details of the selected VFO.
It shows for about 10 secs, or a single screen touch anywhere removes it.

If you select a MEMory or HoME channel on the rig, then touch the screen for this info panel and then you change channels on the rig, this info panel is not updated, until you return to VFO mode, then back to MEMory or HoME mode and reselect the blue panel.

Touching the left right arrows on the VF line change the VFO band up or down. The extra HF channel, 'HFX', always appears between the 70cm and 160M bands.
Touching the VFX readout toggles between VFOA and VFOB.
The larger frequency readout is green to show which is selected.
Touching the MODE readout turns it, and the left right arrows orange. You can scroll through the modes available with the arrows.
Touch MODE area to return to normal.
Touching the POWER readout turns it, and the left right arrows orange. You can scroll between max and min power available for that band with the arrows. Step size varies depending on actual value. Touch POWER area to return to normal.
Touching the left right arrows on the MFx line scrolls up or down through the menu selections.
Touching the frequency readout in the middle brings up the frequency step selector. Touching left or right of the frequency readout alters the step. A touch in the centre again reverts back to normal readout.

> Touching left or right of the frequency readout changes the frequency by the step previously selected, or the default step of 12.5K.


The step selector can have different values for VFOA and B.


Had a slight change in screen layout. Moved PTT down a bit and extended the LoCK functions. (see below).

When you press PTT on the rig or screen, it shows in red. If the rig detects a high SWR it flashes 'SWR' in the display. (see pic below).


Touching the LCK area puts the rig lock on. The different lock types can then be toggled through by touching to the right. You can't alter the lock type by screen touch if it isn't on.

SLW or FST, dial speed.
SQ or GN, Squelch or RF Gain control.

Touching the AGC area puts the rig AGC on. The different options can be scrolled through by touching to the right of it. You can't alter the AGC type by screen touch if the it isn't on.



The display software isn't fault free and I make no claims that it is. Touching the screen in the wrong place in the middle of one process might confuse it. It usually corrects itself if you swap VFO a couple of times with a 5 second pause between presses.

Touching the meter around the +60 area redraws the actual meter.

The older webpage for the Uno and smaller screen can be found here.



The Arduino .ino sketch files contain the software for both variations.
They are available on Ebay for 10, or by contacting me directly.


scat @ m6yif . co . uk

I've started a
'Closed' Facebook group that just buyers can have access to. 
Further updates are posted on it, or you can have them via email if you request.