SmartTweezer Clone

millwood0 · 发表于 2010-7-19 05:29:33

SmartTweezer (http://www.advancedevices.com/products_tw.htm) is an interesting product, with many desirable functions, like R/L/C measurement.

it is unfortunately quite pricy.

so what about making one using a mcu? the original SmartTweezer uses a msp430 (for low power consumption?). since I have a bunch of pics, that's what I will use.

a short list of design goals:

1) portable code in C.
2) measures r/l/c plus their combinations (R+L, R+C for example) so that it can measure ESR for a capacitor.
3) other functions: probe / logic analyzer, signal generator, frequency meter, timer / time base generator, servo signal generator, diode tester (Vf @ Ifwd), uart / rs232 generator / receiver, etc.

hardware:
1) mcu: 16f886, should be sufficient
2) display: 16x2 lcd - cheap and portable.

it may take me a while so be patient.

cyberjok · 发表于 2010-7-19 05:41:09

好东西啊，呵呵！实用！楼主打算DIY一个啊！

eezm · 发表于 2010-7-19 07:36:53

支持楼主将这个项目进行到底，耐心等待，随时关注。

110911 · 发表于 2010-7-19 07:54:07

RMB 2000Y 支持楼主！

wmm20031015 · 发表于 2010-7-19 08:03:50

这个不错

wangqh1983 · 发表于 2010-7-19 08:23:35

回复【楼主位】millwood0
-----------------------------------------------------------------------

顶！

fickle · 发表于 2010-7-19 10:50:20

确实是个好主意。

也考虑做这个东东。一种做这个镊子的，另一种做100kHz+。我的想法放弃7135这种模拟的，倾向于数字的。

我觉得难点如下，

1、如果用内部adc，关于mcu内部算法如何考虑的呢？

2、msp430 功耗极低，很少有产品超过它。（whatever）

exploer · 发表于 2010-7-19 10:56:19

关注！

fickle · 发表于 2010-7-19 10:57:42

楼主不会采用那种双积分形式吧？

据我的意见，这种看似简单，可完成它，个个是顶尖顶尖模拟高手！hp算一个，那个m3的老头都搞了几十年啦。

JQ_Lin · 发表于 2010-7-19 12:42:08

耐心等待。
顶！

fickle · 发表于 2010-7-21 06:52:49

DIY RLC智能测量仪<简易LCR电桥>讨论

http://www.ourdev.cn/bbs/bbs_content.jsp?bbs_sn=3823454&bbs_page_no=1&bbs_id=3041
---------------------------------------------------------------------------------------
这个帖子，是论坛高人讨论的。提出了3个电路，

1、德国人做的。也许和你的测量思路一致。

2、俄国人的电路。类似的有商业化产品在出售，阿莫有放出它的照片。

3、pic比赛的电路。（以为设计者没有理解测量原理，路子走偏了。不过，他说精度可以达到1%。于是，我想加进上面2个降低snr方

法，可以做的更好。）

millwood0 · 发表于 2010-7-25 05:25:30

some progress.

here is the basic framework. no real functionality yet.

implemented:

1) the display routines;
2) a framework to add functions easily, without major programming changes
3) the ability to put the probe into sleep and wake it up
4) utilizes the onboard eeprom to save probe status before goes into sleep and retrieve the status after waking up from sleep
5) consistent pin initialization so to minimize power consumption while in sleep.
6) allows probe-controlled back lighting for the led - to save on current consumption.

millwood0 · 发表于 2010-7-25 05:31:23

here is the schematic.

R1 is the current limit resistor for the input pin (RA0 and RC0 for clock). R2..R5 are to change the voltage on the input.

R6..7 are the pull up resistors - they may not be needed if your target chip has weak pull-up.

BUTTON_P is the primary mode button - it cycles through the various mode.

BUTTON_S is the 2ndary mode button - it cycles through the sub modes within a main mode.

the HC164 is for my development board since it uses a 3-wire lcd connection but it can be replaced.

(原文件名:super probe 1.PNG)

millwood0 · 发表于 2010-7-25 05:33:16

here is the code, with the .cof file.

点击此处下载 ourdev_570538.rar(文件大小:21K) (原文件名:16F886 Super Probe.rar)

cyberjok · 发表于 2010-7-25 05:44:05

好，为什么不选带CTMU的PIC啊，最好支持XLP的

j805 · 发表于 2010-7-25 07:51:33

mark

millwood0 · 发表于 2010-7-25 08:19:20

I added logic probe, volt meter, and diode tester.

here is a running simulation for the diode tester.

Push BUTTON_P to get to the diode mode; and then SW2 to select either a led or a 1n4148 to test.

then push BUTTON_S to cycle through the 4 sub modes under the diode tester: it measures the forward voltage drop on a diode at four different current levels.

(原文件名:super probe 2.PNG)

millwood0 · 发表于 2010-7-25 08:21:33

in the above example, the diode under test, has a forward voltage drop of 713mv when 4.287ma of current flows through it.

here is the code base, including the sim file, source file + the .hex file.

点击此处下载 ourdev_570542.rar(文件大小:18K) (原文件名:16F886 Super Probe.rar)

redbat_228 · 发表于 2010-7-25 08:28:07

很有创意，支持一个…

millwood0 · 发表于 2010-7-25 08:37:44

someone really wanted to see what the forward voltage is on a diode when powered by a 10Mohm resistor, :)

here it is.

notice that the diode is powered by RB4 through a 10Mohm resistor now.

enjoy.

(原文件名:super probe 2 - 10M.PNG)

since the change is minor, I will post the revised code next time.

millwood0 · 发表于 2010-7-25 08:38:34

the real reason for adding that 10Mohm resistor is to that we can measure very small capacitors later, :).

JQ_Lin · 发表于 2010-7-25 17:38:17

谢谢 millwood 。继续关注。

fickle · 发表于 2010-7-28 23:46:53

以为楼主的路子走偏了。

cyberjok · 发表于 2010-7-29 06:54:25

只是软件模拟没有什么意思，呵呵

SmartTweezer Clone

阿莫论坛20周年了！感谢大家的支持与爱护！！