The Digispark can be configured as a HID Keyboard. Also ATMEGA32U4 boards:- Arduino Leonardo, Bad Beetle Pro Micro, OTG connectors and cables and a Wire to disable typing, can be used. Useful for auto testing a typing app.
My AutoTyping kit. DigiSpark, ATMEGA32U4 boards:- Arduino Leonardo, Bad Beetle Pro Micro, OTG connectors and cables and a Wire to disable typing. :-
This page explores a peer to peer protocol , but pragmatically a master slave protocol is simpler.
It has a USB port for the HID and three pins.
There are three pins P0, P1, P2. P1 has an LED so in an output.
We want an ASTABLE - when one end is typing, the other end backs off. Turn the LED on when Typing, if the other end has LED on, back off typing.
if one is the master and the other the slave connect P0 on the slave to P1 on the master
Explore peer to peer so
----|----|----|----|----|----|----|----|----|----|----|----|
+---------+
|DigiSpark|
+---------| P2 |==> USB HID keyboard
| +-------| P1 LED |
| | +----| P0 I/P |
| | | +---------+
| | +-- /DISABLE P0 is used to disable typing
| | P1 is LED output
| | P2 is Fast / slow
| | +-- /DISABLE
| | | +---------+
| | | |DigiSpark|
| | +----| P0 |
+---------| P1 LED |
+-------| P2 I/P |==> USB HID keyboard
+---------+
enable pullups on the inputs.
----|----|----|----|----|----|----|----|----|----|----|----|
The units type either fast or slow. When TYPING turn on the LED
LED __^--- Start of typing - back off
LED --v___ GA invitation to start typing
There is a deadlock if both ends are not typing and the LED is off.
So run a watch dog timer and pulse LED if it matures to kick other end.
Pragmatically it is easier to let them free run.
set up different text at each so the loop takes a different time.
ELSE alternatively let one be the master and the other slave.
On the slave enable typing when the master is not.
"1" --- [ p0 master p1] --- [ p0 slave p1 ] ---
Inputs:
P0 HALT - stops typing - needed for reprogramming.
P2 TYPING - hold off starting typing, type to end of sentence.
Output:
P1 TYPING - Indicated Unit is TYPING SENTENCE.
* Type till end of the sentence
* Hold off starting until IDLE on P2
* If interconnected, P1 output => P2 input
* Use weak pull ups on inputs. P2 HIGH when IDLE, so P1 HIGH when IDLE
P0 input HALT - use to stop typing to reprogram
P2 input HIGH = IDLE - default Pulled up.
P1 output LED OFF when TYPING, ON WHEN IDLE
modules
[ holdoff logic ]
states: ( not typing ),( typing ), ( handover Sequence )
[ typing engine ] - type up to GA
[ UC1 ] [ UC2 ] two micro controllers programmed as HID keyboards
Code expriments in JavaScript on this webpage.
process1() is called on a timer tick
processUC_1(), processUC_2(), processUC_wiring() is called on a timer tick
-----+-------+---- Wired OR buss using Weak Pullup resistors
| |
[ UC1 ] [ UC2 ] two micro controllers programmed as HID keyboards
//
// processUC_1 is instance 1 in one micro controller
// processUC_2 is instance 2 in another micro controller
// processUC_wiring is interconnect wiring
//
// [ processUC_1 ] , [ processUC_wiring ] , [ processUC_2 ]
//
----|----|----|----|----|----|----|----|----|----|----|----|
+---------+
|DigiSpark|
+---------| P2 W-OR |==> USB HID keyboard
| +-------| P1 LED |
| +----| P0 I/P |
| | +---------+
| +-- /DISABLE P0 is used to disable typing
| P1 is LED output
| P2 is Fast / slow
| +-- /DISABLE
| | +---------+
| | |DigiSpark|
| +----| P0 |
| +-------| P1 LED |
+---------| P2 W-OR |==> USB HID keyboard
+---------+
----|----|----|----|----|----|----|----|----|----|----|----|
P0 input HALT - use to stop typing to reprogram
P2 Wired OR buss - Assert low while typing, Holdoff starting typing till high.
P1 output LED OFF when TYPING, ON WHEN IDLE
There are two streams to be displayed together.
Options:
Display two lines:- received, transmitted.
Merge characters as they arrive.
Merge Words as they arrive.
Merge ParaGraphs as they arrive.
Add time Markers so split on.
The input needs to be display at least word by word.
Flushed 1:hsgdhsgdhs 2:khasahsksahk --------------------- Line1: jwhej kjwejk kjwhejkwle l Line2: kwh ek jknmnm ljkljj -------------- When Line1 or Line2 get too big flush some text out to the Flushed buffer. Build up string consisting of a list of app + TRA interleaved. opStr = opLogStr+
You could draw a timeline as characters are received.
If people are overtyping, then the bubbles split.
If the bubbles are split on GA, then the Bubbles can overlap in time.
A--[ txBuffer ]---- B--[ rxBuffer ]---- =================== stream Timeline:- =================== A--[ HI GA ]-----------------[Hello ]-----[Hello ]---[aaaaaaaaaaa]--------[ddddddd]-- B----------------[ HI GA ]-----[Hi]---------[hhhhhhhhhhhhh]----[bbbbbbbbbbb]---[ccccccc]----So do you have bubbles that are not overlapping, that overlap. If they overlap, does the text go at the start, middle, end?