Is this schematic right?
MichaelN,
I tried your schematic(minus the MCU) w/ a 2N 5308 NPN Darlington but there still is no signal. Am I using the wrong transistor? Or is there anything wrong about my receiver?
Compared to normal AVR programming Arduino is simple. It’s C based so it may not be quite as easy as PICAXE or BASIC stamps but the C they use is simple enough to learn quickly and a lot faster than the other two.
Now taking a step back you’ve said what you want to do in your project but why are you doing the project? There’s a lot of skilled people on here and they may have approaches to the problem you might not have thought of but we need information.
In short…
What problem or task is this meant to solve or perform? (not just reset a timer, what’s the timer for?)
What distance do you want this to work at?
What’s your budget?
What tools do you have?
What power source do you have in mind?
I see that a lot has been posted when I got distracted writing this so bear with me.
Hi Trigger,
I’ll answer your questions
- The timer is for an alarm. I’m trying to make an anti-lose alarm that is going to sound when the receiver/timer does not receive a pulse to reset it.
2)This distance has to be a maximum of 10m(30ft) but I might consider a potentiometer to change that.
3)Nothing more than $50, that’s my allowance.
4)All I have are my hands. a few breadboards, and wire, so I think I’m better off with DIP ICs.
5)Batteries. AA, AAA, or CR2032. They are found at the dollar store so it’s very cheap.
Also, do you think Arduino might be a little overkill?Here are my reasons:
-
I’m trying to make my project as small as possible and the Arduino, although it fits in a palm but it’s a bit too big for my uses.
-
There will be a lot of pins that are not used so I think it doesn’t take it to its full potential(I have big hopes for this one)
-
Since it operates at 5V, wouldn’t that raise the transmission range?
With that much money then every penny counts. I’d suggest you look at this.
https://estore.ti.com/MSP-EXP430G2-MSP4 … P2031.aspx
$4.30 US you get two microcontrollers, and a programming/breakout board.
MSP430’s are a bit more difficult to program when compared to PICAXE or Arduino, but the price is right. The sooner you learn C the happier you will be later. That will leave you more money for other parts. It’ll also do wonders for battery life since PICAXE generally doesn’t do power management.
This is another one, though all in one.
https://estore.ti.com/EZ430-RF2500-MSP4 … P1148.aspx
You get two boards, a USB programmer/debugger and a battery pack. It has everything you need so it just needs to be programmed. You’ll be surprised how small they are too. It’s C programming again so you’ll have a steep learning curve.
I don’t normally use MSP430s myself being an ARM and AVR fan but the dev kits are neat enough to use for occasional projects.
Nice but I only have a week and I have 2 other projects so shipping time is also very important. I’m willing to raise my budget for shipping fees but are you sure they are reliable?
Here are two block diagrams
MichaelN:
As for the Arduino / PICAXE, if you’re prepared to spend the time to learn and read instructions you should be able to use either. If you need to do this in a hurry, and you haven’t previously programmed microcontrollers, you’d be better of using encoder / decoder chips such as the Holtek types previously discussed.
Trigger:
Compared to normal AVR programming Arduino is simple. It’s C based so it may not be quite as easy as PICAXE or BASIC stamps but the C they use is simple enough to learn quickly and a lot faster than the other two.
They are conflicting. I need a good MCU choice for my backup plan that is not going to make me say,"I don't like [insert MCU name here] anymore, I guess I'll go with the [insert MCU name here]."Trigger:
MSP430’s are a bit more difficult to program when compared to PICAXE or Arduino, but the price is right. The sooner you learn C the happier you will be later. That will leave you more money for other parts. It’ll also do wonders for battery life since PICAXE generally doesn’t do power management.
The criterion I’m considering are:
1)learning speed
2)availability
3)price
4)size
5)battery life
6)beginner-friendly
Suggestions anybody?
The Kid:
MichaelN:
As for the Arduino / PICAXE, if you’re prepared to spend the time to learn and read instructions you should be able to use either. If you need to do this in a hurry, and you haven’t previously programmed microcontrollers, you’d be better of using encoder / decoder chips such as the Holtek types previously discussed.Trigger:
Compared to normal AVR programming Arduino is simple. It’s C based so it may not be quite as easy as PICAXE or BASIC stamps but the C they use is simple enough to learn quickly and a lot faster than the other two.They are conflicting. I need a good MCU choice for my backup plan that is not going to make me say,"I don't like [insert MCU name here] anymore, I guess I'll go with the [insert MCU name here]."Trigger:
MSP430’s are a bit more difficult to program when compared to PICAXE or Arduino, but the price is right. The sooner you learn C the happier you will be later. That will leave you more money for other parts. It’ll also do wonders for battery life since PICAXE generally doesn’t do power management.The criterion I’m considering are:
1)learning speed
2)availability
3)price
4)size
5)battery life
6)beginner-friendly
Suggestions anybody?
Learning speed: BASIC (Basic Stamp, PICAXE), Arduino (Simple C style), MSP430 ( you’re going to learn memory locations and C without the kid gloves)
Availability: All about the same
Price: MSP430 is the winner here because you get a full dev kit for under $5.00 the EZ kits start at $20
PICAXE starter kit is about $15
Arduino
BASIC stamp… a stamp by itself is like $45
Size: All relative but that depends on the package. The EZ kits for the MSP430 use tiny boards that are smaller than a quarter, all you do is hook up the IO and power.
The PICAXE DIP package
BASIC stamp by itself is fairly small.
The Arduino has everything in place so size can be misleading, you just have to hook up the IO
Battery Life: MSP430 hands down it’s power usage can be measured in uA
The Arduino actually runs on an Atmel picoPower capable chip though I don’t know if you can use the
features of it from the programming environment they use.
The BASIC Stamp and PICAXE though the two with the Arduino are probably close.
Beginner friendly: BASIC so I’d say the PICAXE over the stamp
Arduino, it may be C but it’s kind, fluffy C and there’s a huge following.
MSP430 is low level C so you’re manually setting registers.
My suggestion would be the Arduino. It’s slightly harder than BASIC but what you learn can be applied to more advanced chips later. If you learn BASIC you’ll have to unlearn some bad habit and then still learn C.
As discussed, you really need proper encoder / decoder chips, or to do the same thing in a microcontroller (which it seems you're going to do).The Kid:
This is my final schematic.
I did use a decoder chip in my receiver schematic. If you look closely, I used an HT-12D.
So you did - I must be going blind!The Kid:
I did use a decoder chip in my receiver schematic. If you look closely, I used an HT-12D.
Oh, and another thing, is my schematic right? Is there anything that looks lousy or could be wired differently?
Do you want the output to go high only momentarily (ie, while valid data is being received)? If so, you should use the "VT" pin instead of the data pins (D0-D3).The Kid:
Oh, and another thing, is my schematic right? Is there anything that looks lousy or could be wired differently?
If you want a latched output (ie, it remains high until different data is received), then you can use the Data pins, but you shouldn’t join the pins together like that. Just use one of the Data pins. Joining them together could potentially make them “fight” (and draw a high current) if some of them want to go high, and others low.
OK I got it. But can I have your voice on the Arduino vs PICAXE debate? It could help me a lot.
Sorry, I've never used either. I've always taken the hard route of using the microcontrollers directly on my own PCBs, then programming in C and loading the code using JTAG programmers. Probably not the recommended option for a beginner :)The Kid:
OK I got it. But can I have your voice on the Arduino vs PICAXE debate? It could help me a lot.
Read the materials on the Arduino web sites.
Read the beginner’s page tutorials on the AVRfreaks.net forum. If you are polite, the guys on that forum will be more than happy to help you get started.
OK. I got an Arduino from SFE but it’s on backorder. Right now I don’t think that I will need an Arduino so I guess I’ll use it for other purposes. Thanks everybody!
PS: This thread might not be finished. I might need some help if my circuit w/ the encoder and decoder doesn’t work.
IMPORTANT !!!: I totally forgot to mention the encoder. I’ll post a schematic very soon.
On the HT-12E there are 5 Input pins that I can use, D0-D3 and Transmit Enable. Which one(s) should I use? If I don’t use TE, do I plug TE to Vcc, GND, or leave it floating?