OK... That ain't gonna work. Attiny84 is at 89% program space with just the required libraries loaded.
How do you (or can you) add an ATTINY chip to the IDE environment when you can't find it in the boards manager
I want to use a ATTINY1604 and it's nowhere to be found in the ATTINY boards manager.
Edit. OK found that..... BAFFLING mount of selectable options now in the board manager.
I assume i would want to use OptiBoot?
Why do you insist in an ATtiny instead of using one of the supported Arduinos?
Footprint.... a 14 pin soic is considerably smaller than the smallest Arduino I know of.
Just trawling through 548 pages of datasheet to see if it declares the recommended size of the caps to go on the external crystal.
Can't you sort out those controllers with insufficient memory?
From the ATTiny24... datasheet:
The optimal value of the capacitors depends on the
crystal or resonator in use, the amount of stray capacitance, and the electromagnetic noise of the environment. Some initial
guidelines for choosing capacitors for use with crystals are given in Table 7-3 on page 26. For ceramic resonators, the
capacitor values given by the manufacturer should be used.
That is the datasheet for just the 1604. It's OK, I assumed it was 8Mhz internal, but its actually 16Mhz and 20Mhz internal ,so I can use that.
It compiles my demo code fine.
I'll get a couple and breadboard it
Err....
OK, My sensor is 3.3v. Therefore the I2C lines are 3.3v
My Attiny1604 has to run at 5v, because it is outputting to an RGB strip and that data level needs to be 5v minimum.
Therefore the I2C to the sensor is going to need level converting. How annoying.
Can this be achieved with a simple voltage divider, or does I2C require a more 'efficient' way (as in dedicated level shifter)?
The other option I suppose it to run everything at 3.3v and only level shift 'up' the RGB output. That actually might be easier.
OK. I will run the whole pcb at 3.3v instead. That actually makes life easier on a few other fronts too (like interfacing with a Teensy 4.1 at a later date).
I will try this...
Ideally, a 74AHCT125 would level shift the signal to the RGB led (due to timing), but I don't really have the space, and that is a big chip to shift only one signal.
Best option is to try it and and see.
Sn74lvc series single gates in SOT packages.
Could you clarify the nature of the 5V connection to the RGB strip? Is it I2C (bidirectional) or something else?
Just driving 2x SK6812 RGBW 5050 leds (5v) from a Attiny1604, using the basic NeoPixel library.
So it's just 1x PWM TX and that is it.
Ok, so either shifting mechanism should work. But the chip would be faster if that makes any difference. But be careful about single gate chips. 74ALVC only requires 2V input as high, but 74LVC requires .7xVcc, which would be 3.5V. I don't think there is a single gate 74ALVC125.
Actually, your best bet might be replacing the N-channel mosfet with an NPN. That would use a bit more current, but has much less capacitance. Delete the 10K pullup on the 3.3V side, but add a base resistor, maybe 47K or 100K.
I was thinking specifically of the SN74LV1T125 in the SOT-23-5 package.
Yes, that one should work fine.
I like the Little Logic concept. it makes circuit board layout much easier if you need single gates at various places on the PCB.
OK, I will look at the SN74LV1T125.
I have an ongoing order to place with RS... Annoyingly, they don't appear to stock them.
I'll have to see if I can find a connection diagram for my needs
I don't know what sort of backwater location you are in but if you are in the UK, you can choose from companies like Mouser, Digikey, Farnell, etc that will give you access to a huge catalog of parts.
So, just for fun, I built an order for 10 ea. of the SN74LV1T125 from Mouser UK to be shipped to the Bear Hotel where I've stayed in Hungerford, Berks.
Now, mind you, £1.85 each is a steep price to pay for the part but assuming you ordered a bunch of stuff at the same time, the per part cost would drop, shipping stays the same, and you would be assured of getting real parts instead of counterfeits from China. That order would arrive Dec 11, BTW.
Yea fine if I want to blow some huge amount to meet a minimum order amounts for Farnell, Digikey, Mouser etc... but I have stuff to get from RS and my budget is limited, I can't afford to use multiple suppliers. Sorry if I am not rich enough yet.
I see your order there, but on my budget... £12 wasted on postage is mad for £3.42+vat worth of goods.
I have to use RS in this case, as none of the other suppliers have certain parts I need (and they can't be equivalents... e.g. certain types of crystal displays).
I hate RS. Their site search engine sucks, but it is what it is.
There are no minimum quantity requirements for any of those suppliers. They don't offer free shipping for a certain order value if that's what you mean. RS charge £8 for orders under £50 so I guess you could say they have a minimum quantity requirement. Their catalog is extremely limited so that makes them undesirable though.
If RS had the SN74LV1T125, you would save £5 if you bought 10 from them. But they don't have them so you won't be able to take advantage of that part at all. If you spend a little time thinking about your design, you could order several parts at once instead of wasting money on shipping the project in piecemeal.