ZBasic Forum

Got it, thanks.

I'm coming back to AVR from an excursion into STM32-land, and I'm somewhat amazed to find all the things I don't remember or never knew...

--jim

Is it ok to change the ADMUX register in the ATMega644P to use an external reference, but then still use the ZBasic intrinsics to read the converter? The reference would still be roughly equal to VCC, but come from a precision regulator with a decoupling filter. (This is in the context of the "...

Figures... I thought it would be hard. I'll be in touch on the ZX-24su . Thanks, --jim You have a number of different options here: 1. You could use I2C but don't forget the 2 pullup resistors (2.2K-6.8K) on SDA and SCL. 2. You could use an external EEPROM but connecting to the extra pins on the ZX-...

Hi folks, Any suggestions as to adding external, non-volatile user data storage to (for example) a ZX-40n? In the ZX-40p configuration, I see there's an ATMEL serial EEPROM hooked on to the top half of Port B. If I duplicated that with a ZX-40n, could those pins be accessed from ZBASIC for accessing...

This is an update on the previous I2C LCD code that implements most, but not all of Don Kinzer's suggestions.

Thanks, Don. I'll get the single char and int output functions in there ASAP.

--jim

Mike Perks suggested I try an I2C LCD instead of RS232 because of the much faster speed. I ordered a Newhaven Displays 4x20 white-on-blue, I2C-capable LCD. Works great with the ZX128ne using pins 11 and 12. Newbie alert - don't expect clean, Zen-like code. My total time with the device and ZBasic is...

Here's the data set for the encapsulated 10K thermistor being discussed. It's actually a subset of a much larger table. Since the source is a printed table we only hand-entered as much data as we thought we needed for a 60-105 degree F working range. The curve-fitting software is CurveExpert 1.4 , a...

If you bound the function you're fitting with, judging by how your data curve looks you should be able to get away with something substantially less than 8th order. Also, have you tried an exponential? Attaching the data points to your post might be useful. Embarrassingly enough, I checked the data...

Thanks, Mike. In the measured data set, the X values are indeed consecutive integers so the interpolation for x[y=0] : x[y=n] is straightforward, except where y=0. ;-) (sorry, couldn't help it) Your comments about interpolation triggered a thought... if we make the ADC readings periodic at some know...

> ... To do this, connect the SSR opto anode (the + control input) to Vcc and the cathode(-) to the processor pin. In code, set the pin low to turn the relay on and set the pin to high-impedance to turn the relay off. High-impedance is also the Reset pin state, so the relay will be off when the pro...

Just based on specs, it looks like driving a Kyotto KD20C40AX solid-state relay directly from a ZX-40 I/O pin should be ok. Anyone have any experience with that either way? The ATmega644 data sheet shows that with VCC=5V, the minimum voltage of a high pin is 4.2V . The SSR data sheet shows that with...

This is an interestng thread. Is the decision to go with an 8th order equation due something like "2 different 4th order equations interacting will need an 8th order equation for complete description"? Or will a 5th, 6th, or 7th order be sufficient? Hi Tony, It isn't a direct relationship...

"Difficult" in this case has to do only with external requirements. not comparing the methods. I know I'm not being completely clear, sorry. As for the rest, that gets complicated. You're correct that a garden-variety thermistor should be adequately modeled with a 4th-order polynomial. In ...

Thanks for the reply. Not having used one yet, I wanted to find out if there were any 'gotchas' with using floating point math on the devices. I understand it would be slower than a binary search on a small table, but depending on the implementation, "slower" can mean half as fast or 1/50t...

Hello, For ZBasic devices running "native", does anyone have an opinion as to the plusses and minuses of using a 50-element lookup table of 16-bit integer values versus an 8th-degree polynomial fitting function? The (single precision) polynomial function would look like this in BASIC: y = ...