I would be interested to know exactly what you feel are the 'awful number of limitations'
Most of the reasons why I think its limited are due to the software.
The only hardware complaint is its not very small.
While board area doesnt matter much, yours is rather thick.Here is a list of software issues I can think of in my jet lagged state.
- Its not open in any sense of the word. The chip is a black box.
- Fixed serial speed.
- You can only use serial while SPI and I2C can be more useful in many circumstances.
- No feedback. I'm thinking of implementing 'slow down' feedback so if the buffer gets full then data isnt lost.
- Its a 'dumb' chip. It only does what its told. It cannot do any cool things like automated custom character animation or ticker displays which are perfectly possible and reduces the load for the device controlling it.
- It cannot be upgraded. If Peter makes a new version then you need to buy a new chip.
The board size is dictated much by the real estate required for the various hole sets to connect to various pinouts, and by my desire to keep the board as a through-hole project to make it useable by a broader range of hobbyists. the ExpressPCB boards is a bit thick, but since I aimed it at being hung onto the back of the display by it connector, the extra thickness serves to strengthen the board.
Granted it is 'closed.' Peter's chip is proprietary. The income through the years from that chip alone has gone a long way to fund projects for his students. I have no problem with that. As for 'upgrades' and 'having to buy a new chip' there's been one upgrade almost two years ago and a 'silent' upgrade (no chip designation change) two months ago (Fixed a bug John Carter and I each discovered independently that had been around for three years without being discovered).
I don't see fixed baudrate as a problem. The tradeoff in variable baudrates can be erratic, unpredictable startup.
No Feedback ... that would be nice, the cost is another connection and i/o line
SPI/I2C ... yes, it could be handy, but again more complexity.
You are right and wrong about 'special features' there is some provision to send binary commands that could enable dot-row/column scrolling and other 'special effects.' But that indeed does pass an increased burden on the host processor.
cheers ... BBR