{"id":17,"date":"2014-01-01T13:00:00","date_gmt":"2014-01-01T13:00:00","guid":{"rendered":""},"modified":"2023-08-18T12:19:07","modified_gmt":"2023-08-18T11:19:07","slug":"diy-dro-for-mini-mill","status":"publish","type":"post","link":"https:\/\/blog.hslracing.com\/electronics\/2014\/01\/diy-dro-for-mini-mill.html","title":{"rendered":"DIY DRO for Mini Mill"},"content":{"rendered":"

Having settled on some\u00a0Igaging<\/a>\u00a0linear scales\u00a0and Yuriy Krushelnytskiy’s\u00a0DIY DRO<\/a>\u00a0for Android as mentioned in my Mini Mill posting<\/a>\u00a0I set about making the board itself a cheaper prospect.<\/p>\n

I am not a big fan of the Arduino<\/a> boards and their associated shields, as they use a non-standard pin spacing from one side to the other, which is incompatible with 0.1″ perfboard or stripboard, simply so distributors can charge a premium for the boards and shields, many of which do not contain more than a few pennies worth of components.<\/p>\n

I can understand the convenience factor and the “plug and play” nature of the shields, however personally I am not willing to pay the premium for them. I would rather spend a little more time on a breadboard or with Eagle<\/a>\u00a0designing a more minimalist solution that only uses the components actually required.<\/p>\n

At least the Launchpad<\/a>\u00a0platform from Texas Instruments is almost compatible with standard 0.1″ perfboard (it does fit, but the pins will be at a little bit of an angle).<\/p>\n

Both solutions proposed by Yuriy make use of a 20 pin chip – ATmega328P<\/a> on the\u00a0Arduino<\/a>\u00a0Uno\/Duemilanove\/whatever and a MSP430G2553<\/a>\u00a0for the\u00a0Launchpad<\/a>, now considering that only 5 I\/O pins are actually being used (6 if you connect RX and TX from the bluetooth module), this is a little overkill.<\/p>\n

A better choice of chips would be the 14 pin\u00a0ATtiny24\/44\/84<\/a>\u00a0from Atmel or the MSP430G2231<\/a>\/MSP430G2211<\/a>\u00a0from Texas Instruments, you are still wasting half the I\/O pins, but going smaller still does not really have enough pins.<\/p>\n

I have chosen to draw up the circuits with the additional battery, diodes and smoothing capacitor as mentioned in one of Yuriy’s other posts<\/a>.<\/p>\n

ATtiny version:<\/p>\n

\"\"<\/a><\/div>\n
Single sided board layout with earth plane 45mm x 40mm (1.75″ x 1.6″):<\/div>\n
\"\"<\/a><\/div>\n
The MSP430G version does not require all of the other resistors as it has built in pull-up\/down resistors:<\/span><\/div>\n
\"\"<\/a><\/div>\n
Single sided board with earth plane 40mm (1.6″) square:<\/div>\n
\"\"<\/a><\/div>\n
Perfboard version drawn using\u00a0DIY Layout Creator<\/a>, The battery used here is a 3V CR1220 (bottom middle connections):<\/div>\n
\"\"<\/a><\/div>\n
In all cases the bluetooth module sits over the top of the battery saving yet more space.<\/div>\n
<\/div>\n
Turning the board 90 degrees, is possibly a better layout it would even be possible to use Female USB type A connectors, that way no cables would need to be cut (\u00a31.93 for 10 and free shipping from ebay<\/a>).<\/div>\n
\"\"<\/a><\/div>\n
I have several of each of these various chips, the\u00a0ATtiny44<\/a>\u00a0chips cost me \u00a31.13 each from RS<\/a>, the\u00a0MSP430G2211<\/a>\u00a0cost me $12.90 for 3 x launchpad kits each of which came with a\u00a0MSP430G2211<\/a>\u00a0and a\u00a0MSP430G2231<\/a>\u00a0chip, so almost free if you assume $4.90 for the Launchpad \u00a0and one chip (now $9.99), or you could simply order some free samples from Texas Instruments<\/a>.<\/div>\n
<\/div>\n
The board, capacitors and diodes cost pennies, the most expensive part is the bluetooth module at around \u00a34.80 – they pretty much all work on 3.3V or 5V, or any voltage in-between (as do the micro-controllers).<\/div>\n","protected":false},"excerpt":{"rendered":"

Having settled on some\u00a0Igaging\u00a0linear scales\u00a0and Yuriy Krushelnytskiy’s\u00a0DIY DRO\u00a0for Android as mentioned in my Mini Mill posting\u00a0I set about making the board itself a cheaper prospect. I am not a big fan of the Arduino boards and their associated shields, as they use a non-standard pin spacing from one side to the other, which is incompatible…<\/p>\n","protected":false},"author":2,"featured_media":92,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[3],"class_list":["post-17","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorised","tag-dro"],"_links":{"self":[{"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/posts\/17","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/comments?post=17"}],"version-history":[{"count":5,"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/posts\/17\/revisions"}],"predecessor-version":[{"id":172,"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/posts\/17\/revisions\/172"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/media\/92"}],"wp:attachment":[{"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/media?parent=17"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/categories?post=17"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/tags?post=17"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}