Wow, that's a flash one. It's got digital displays. :) My old 603B has developed a fault or two. Anyone got a schematic they want to share or know a website that hosts one?
Yes, you could use my 10MHz DDS generator project:
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Also a multiplexed 7seg LED display, say 4 digits with transistor sinks.
- RS232 chip and DB9 connector
- USB Interface
- Various power supplies (most important), say fixed +/-15V, +/-12V,
+/-5V, 5V, 3.3V, and one variable supply (0-15V) with adjustable current limiting (0-1A) which goes all the way down to 0V. A switchable AC power supply would be nice to.
- Speaker and buzzer
- A few pots (say 1K and 100K)
- Maybe some general purpose analog blocks like a precision diff-amp and some adjustable filters.
Just had a look at that page, looks good but the PIC firmware is nowhere to be found and you do not sell kits or preprogrammed PICs... makes it hard to build one.
A quick email would have fixed that. Here is the firmware:
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Sorry, haven't got around to putting it back up on the site yet.
No kits or parts?, gave that up, can't please everyone. Some want a full kit, then some complain it's too expensive, some want just the chip, some want just the PCB, some want just the chip soldered to the board, some just want the programmed chip, some want it modified this way or that, some want a completely built unit, some want to buy all their own parts but want me to build it for them, some want me to explain how it works because they couldn't understand the article, some complain when they soldered the chip in backwards or fried it with an iron, some can't get it working and send it back to get it fixed "under warranty"...
Parts are all readily available, those that want to build it can.
Or if you feel you need a DDS oscillator, you could always use this one :
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Which comes with source code (easily hackable to a sweep generator) and works like a bought one. When I went through this exercise, I went for simplicity: + and - 15 volt supplies, + 5 volt supply all with selectable current limit (I used
30ma,200ma and 1 amp) access pairs of banana sockets with shorting switches to insert current meters or external PSUs, a few BNC sockets with flying pins to avoid having scope probes mucking up the work area, LEDs to let me know when any of the rails were current limiting & that's about it. Lately the 5 volt supply has sprouted a 3.3 volt option switch. M M
I plan to but that will probably be standalone as part of a RF testbed unit i want to build
...hmm the chip itself is only $26.50 AUD and i've already got the 50MHz osc's...
Why not since i'm putting in a meaty AVR uP probably the Mega32 @ 16MHz and a 20x4 LCD and a couple of rotary encoders it's basicly software only (and one bleeping small chip, but it cant be any worse than those dallas semi tsop's!) after that.
great i'll just buy a .5mm tip for my Hakko!
ahh! also use the AVR to give me volt/amp readouts on the p/s
The rs-232 will go in allong with full breakout box facilitys and a max232 so i can testbed micro's, but main comm's will be a USB serial module hooked to the AVR.
also bnc, rca, rj-45, and screw terminals
also use turned pin ic sockets for the connection pins
The current limiting on the power supplys is something i should have thought of (there goes the pc psu idea!) i'll try to set the voltages and curents from the AVR via programmable resistors. I need to be able to produce a skew in the outputs +/- a volt or so to test stability (a fair bit of the stuff i do goes into hostile enviroments)
very, but i'll probably stick to my variac
absolutely yes! if i never have to hunt around for one of these again it will make the whole thing worth it!
If i go with the filters i'm tempted to put in a Cypress PSoC, but i dont want to learn another uP
Thank you very much Dave
The article you did for SC inspired me to play with the ad9835 it's an amazing chip!
i'll probably use a plug in osc for this then divide using some ttl and the micro i'm building in
the keys i'll probably do as pushbuttons with debouncers (one problem is i do a but ov 3V work so i will have to switch logic levels
i will use a TPIC2802 8 channel driver as i use these often (i bought a big box of them for a job that didn't come through)
i will do these as a multi colour indicator -Volts red, 0V off, 3-5V yellow and above 5V green (also add an extra led to each with a 100ms one shot to show pulses)
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